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Background: Major barriers to addressing SARS-CoV-2 vaccine hesitancy include limited knowledge of what causes delay/refusal of SARS-CoV-2 vaccination and limited ability to predict who will remain unvaccinated over significant time periods despite vaccine availability. The present study begins to address these barriers by developing a machine learning model that prospectively predicts who will persist in not vaccinating against SARS-CoV-2., Method: Unvaccinated individuals (n = 325) who completed a baseline survey were followed over the six-month period when vaccines against SARS-CoV-2 were first widely available (April-October 2021). A random forest model was used to predict who would remain unvaccinated against SARS-CoV-2 from their baseline measures, including demographic information (e.g., age), medical history (e.g., of influenza vaccination), Health-Belief Model constructs (e.g., perceived vaccine dangerousness), conspiracist ideation, and task-based metrics of vulnerability to conspiracist ideation (e.g., tendency toward illusory pattern perception)., Results: The resulting model significantly predicted vaccination status (AUC-PR = 0.77, 95%CI [0.56 0.90]). At the optimal probability threshold determined by the Generalized Threshold Shifting Protocol, the model was moderately precise (0.83) when identifying individuals who remained unvaccinated (n = 80), and had a very low rate (0.04) of false-positives (incorrectly suggesting that individuals remained unvaccinated). Permutational importance tests suggested that baseline SARS-CoV-2 vaccine intentions conveyed the most information about future SARS-CoV-2 vaccination status. Conspiracist ideation was the second most informative predictor, suggesting that misinformation influences vaccination behavior. Other important predictors included perceived vaccine dangerousness, as expected under the Health Belief Model, and influenza vaccination history., Conclusions: The model we developed can accurately and prospectively identify individuals who remain unvaccinated against SARS-CoV-2. It could therefore facilitate empirically-informed allocation of interventions that encourage vaccine uptake. The predictive value of conspiracist ideation, perceived vaccine dangerousness, and vaccine intentions in our model is consistent with potential causal relations between these variables and SARS-CoV-2 vaccine uptake., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: Despite the emergence of SARS-CoV-2 variants and waning immunity after initial vaccination, data on antibody kinetics following booster doses, particularly those adapted to Omicron subvariants like XBB.1.5, remain limited. This study assesses the kinetics of anti-spike protein receptor-binding domain (S-RBD) IgG antibody titers post-booster vaccination in a Japanese population during the Omicron variant epidemic., Methods: A prospective cohort study was conducted in Bizen City, Japan, from November 2023 to January 2024. Participants included residents and workers aged ≥18 years, with at least three COVID-19 vaccinations. Antibody levels were measured from venous blood samples. The study analyzed 424 participants and 821 antibody measurements, adjusting for variables such as age, sex, underlying conditions, and prior infection status. Mixed-effects models were employed to describe the kinetics of log-transformed S-RBD antibody titers., Results: The study found that S-RBD antibody titers declined over time but increased with the number of booster vaccinations, particularly those adapted to Omicron and its subvariant XBB.1.5 (Pfizer-BioNTech Omicron-compatible: 0.156, 95%CI -0.032 to 0.344; Pfizer-BioNTech XBB-compatible: 0.226; 95%CI -0.051 to 0.504; Moderna Omicron-compatible: 0.279, 95%CI 0.012 to 0.546; and Moderna XBB-compatible: 0.338, 95%CI -0.052 to 0.728). Previously infected individuals maintained higher antibody titers, which declined more gradually compared to uninfected individuals (coefficient for interaction with time 0.006; 95%CI 0.001 to 0.011). Sensitivity analyses using Generalized Estimating Equations and interval-censored random intercept model confirmed the robustness of these findings., Conclusions: The study provides specific data on antibody kinetics post-booster vaccination, including the XBB.1.5-adapted vaccine, in a highly vaccinated Japanese population. The results highlight the importance of considering individual demographics and prior infection history in optimizing vaccination strategies., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Takashi Yorifuji reports financial support was provided by Bizen city. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Objective: Given their vulnerable health status and resource constraints, the perspectives of women with criminal-legal involvement (WCLI) are important but not usually represented in the literature on vaccine interest and vaccine hesitancy. This study aims to examine how the COVID-19 pandemic and vaccine affected the influenza vaccine uptake among WCLI., Methods: A cross-sectional secondary analysis was conducted using data collected from the Tri-City study, which followed WCLI in three U.S. cities from 2019 to 2023. We mapped the distribution of influenza vaccine uptake in 2019-2023 and developed a composite outcome that reflected participants' patterns of Y/N to influenza vaccine, which were categorized into four groups: Influenza Vaccine Supportive, Influenza Vaccine Adaptive, Influenza Vaccine Discontinued, and Influenza Vaccine Resistant., Results: Out of 507 people: 23.7% were Supportive, 8.5% Adaptive, 15.2% Discontinued and 38.3% Resistant. People who received the COVID vaccine had significantly lower odds of being identified as Discontinued (OR = 0.42, 95%CI = 0.20-0.87, p = .020) and Resistant (OR = 0.23, 95%CI = 0.13-0.43, p < .001), compared to the Supportive group. Mistrust toward COVID-19-related information was a significant independent predictor of being Adaptive (OR = 1.59, 95%CI = 1.08-2.35, p = .019), Discontinued (OR = 1.61, 95%CI = 1.15-2.25, p = .006), and Resistant (OR = 1.54, 95%CI = 1.19-2.00, p < .001) relative to Supportive., Conclusions: Vaccine hesitancy poses significant challenges to public health efforts, with apparent dampening effect across vaccines. Public health messaging and clinical interactions informed by best practices in communication tailored to the lived experience of all people, including women with criminal-legal system involvement, will be necessary to inform future interventions aimed at increasing vaccine uptake., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

The association between maternal COVID-19 vaccination in pregnancy and factors such as high risk for severe COVID-19, pre-existing asthma, prior adverse reproductive history, or paternal COVID-19 vaccination during pregnancy, remains unclear. The aim of this study is two-fold: (i) to describe uptake of COVID-19 vaccine during pregnancy by maternal risk for severe COVID-19 and asthma, and (ii) to comprehensively examine individual and familial factors associated with vaccine uptake during pregnancy in Norway. Based on nation-wide registry-linkage data in Norway, we included 101,659 deliveries with gestational length ≥12 weeks, in 2021-2022. Our outcome measure was uptake of at least one dose of mRNA COVID-19 vaccine during pregnancy, using a narrow (first ever dose) and broad (any dose) definition. We fit univariate and multivariate modified Poisson regression models, clustered by county of residency and adjusted for calendar time, to estimate risk ratios (RR) with 95 % Confidence Intervals (CIs). Gestational uptake of any COVID-19 vaccine dose increased from <1 % before mid Aug-2021, to 38.8 % in the rest of 2021, and 48.9 % in 2022. Only 28.8 % and 33.9 % pregnant individuals with high risk for severe COVID-19 or asthma, respectively, received at least one COVID-19 vaccine dose. Paternal COVID-19 vaccination was strongly associated with greater vaccine uptake by pregnant individuals (adjusted RR: 7.2, 95 % CI: 6.8-7.5). Maternal SARS-CoV-2 infection pre-pregnancy (adjusted RR: 0.31, 95 % CI: 0.26, 0.37), familial and individual migrant status were associated with a considerable decreased likelihood of vaccine uptake in pregnancy. History of miscarriage or pregnancy with congenital anomaly were not associated with vaccine uptake. Despite rising COVID-19 vaccine rates in pregnancy, uptake remained low for high-risk individuals. Paternal vaccination, pre-pregnancy infection, migration status, and maternal citizenship were strongly associated with prenatal vaccine uptake. This knowledge can inform tailoring of future vaccination campaigns., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Angela Lupattelli reports financial support was provided by European Union. This work is part of the VERDI project (101045989) which is funded by the European Union. Views and opinions expressed are, however, those of the author(s) only and do not necessarily reflect those of the European Union or the European Health and Digital Executive Agency. Neither the European Union nor the granting authority can be held responsible for them. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: The coronavirus disease 2019 (COVID-19) pandemic disrupted routine childhood vaccination worldwide, especially at the beginning of the pandemic. After the emergence of variants of concern, particularly the Omicron variants, the number of COVID-19 cases significantly increased, especially in children. However, the impact of the Omicron variants on routine childhood vaccination is unknown., Methods: This retrospective observational study collected data on vaccines included in the Japanese national immunization program (NIP) of children 15 years or younger between 2016 and 2022 in Niigata, Japan. During the study period, hepatitis B virus vaccine and rotavirus vaccines were introduced to the NIP in October 2016 and October 2020, respectively. The monthly number of vaccine doses per eligible child population between 2020 and 2022 (pandemic period) was compared to the average number of vaccine doses in the corresponding month between 2016 and 2019 (pre-pandemic period). The effect of 8 surges of COVID-19 patients on trends in routine childhood vaccination was also analyzed., Results: The numbers of doses during the pre-Omicron pandemic period were comparable to the values administered before the pandemic. However, after the emergence of the Omicron variants, and especially after the surge of Omicron variant BA.5 in 2022, the number of vaccine doses declined. The decline was notable in second doses of MR vaccine at age 5-6 years by - 9.6 % and diphtheria-tetanus vaccine at ages 11-12 years by - 14.1 %., Conclusions: Routine childhood immunization was significantly affected by the emergence of the Omicron variants most likely due to the facts that more candidates and their guardians contracted COVID-19, or were required isolation for close contacts. The findings highlight the importance of continued monitoring to maintain high coverage of routine childhood immunizations for controlling vaccine preventable diseases. A follow-up study should investigate changes in the number of declined vaccine doses during Omicron variant predominance., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Yuta Aizawa reports a relationship with Merck & Co Inc that includes: speaking and lecture fees. Akihiko Saitoh reports a relationship with Merck & Co Inc that includes: speaking and lecture fees. Akihiko Saitoh reports a relationship with Pfizer Inc that includes: speaking and lecture fees. Akihiko Saitoh reports a relationship with Mitsubishi Tanabe Pharma Corporation that includes: speaking and lecture fees. Akihiko Saitoh reports a relationship with Osaka University Research Institute for Microbial Diseases that includes: speaking and lecture fees. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Currently, there is limited understanding of the specific humoral immune response in BA.5-infected hemodialysis patients (BA.5-CHDPs) with previous COVID-19 vaccination. Additionally, the relevant risk factors for reinfection with XBB variants in BA.5-CHDPs have yet to be elucidated., Method: A total of 178 BA.5-CHDPs were enrolled in this study among 53 patients who had previous vaccination. To compare hemodialysis patients in both unvaccinated and vaccinated for their immune response to the BA.5 subtype infection, we assessed serum levels of anti-ancestral-S1-IgG, anti-BA.5-receptor binding domain (RBD)-IgG, and anti-XBB.1.16-RBD-IgG using enzyme-linked immunosorbent assay, the neutralizing antibody titer against BA.5 and XBB.1.16 was determined using pseudovirus neutralization assays. Univariate and multivariate binary logistic regression analyses were conducted to identify factors associated with severe infection, the magnitude of specific humoral immunity and susceptibility to XBB variants reinfection., Result: Our findings indicate that BA.5-CHDPs with full or booster vaccinations have higher levels of anti-ancestral-S1-IgG than unvaccinated individuals. However, levels of anti-BA.5-RBD-IgG and anti-XBB.1.16-RBD-IgG are much lower. Booster-vaccinated BA.5-CHDPs have significantly higher levels of BA.5 and XBB.1.16 specific antibodies and neutralizing antibodies than unvaccinated patients. Low globulin levels and shorter hemodialysis duration are independent risk factors for XBB reinfection in BA.5-CHDPs., Conclusion: Although XBB.1.16 specific neutralizing antibody levels were low in BA.5-CHDPs, these levels cannot predict the risk of reinfection; other potential risk factors need to be investigated in the future., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: For pathogens which cause infections that present asymptomatically, evaluating vaccine efficacy (VE) against asymptomatic infection is important for understanding a vaccine's potential epidemiological impact. Regular testing for subclinical infections is a potentially valuable strategy but its success hinges on participant adherence and minimising false positives. This paper describes the implementation and adherence to weekly testing in a COVID-19 vaccine trial., Methods: COV002 was a phase 2/3 trial assessing the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2. Asymptomatic infections were detected using weekly self-administered swabs for RT-PCR testing. We analysed adherence using mixed-effects regression models and estimated the probability of true and false positive asymptomatic infections using estimates of adherence and testing characteristics., Findings: 356,551 tests were self-administered by 10,811 participants during the 13-month follow-up. Median adherence was 75.0% (IQR 42·6-90·9), which translated to a 74·5% (IQR 50·9-78·8) probability of detecting a positive asymptomatic infection during the swabbing period, and between 21 and 96 false positives during VE evaluation. The odds of returning a swab declined by 8% per week and further after testing positive and unblinding. Adherence was higher in older age groups, females and non-healthcare workers., Interpretation: The COV002 trial demonstrated the feasibility of running a long-term regular asymptomatic testing strategy. This information could be valuable for designing future phase III vaccine trials in which infection is an outcome., Funding: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, AstraZeneca., Competing Interests: Declaration of competing interest MV, MNR, KRWE and AJP are contributors to intellectual property licensed by Oxford University Innovation to AstraZeneca. MNR has been an investigator on vaccine trials outside the scope of this manuscript that have received support from and/or have been sponsored by AstraZeneca, ILiAD Biotechnologies, GSK Vaccines for Global Health and VBI Vaccines but all funding for these projects was paid directly to the University of Oxford. AJP reports unpaid work as the Chair of UK Department of Health and Social Care's Joint Committee on Vaccination and Immunisation and a previous member of the WHO Strategic Advisory Group of Experts on Immunisation. LRW, JPJL, NCG, JH and DJP declare no conflicts of interest. The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Lucy Williams, Nicholas Grassly, Katherine Emary reports financial support was provided by UKRI Medical Research Council. Lucy Williams reports financial support was provided by Imperial College London. Andrew Pollard reports a relationship with United Kingdom Department of Health and Social Care that includes: non-financial support. Andrew Pollard reports a relationship with World Health Organization that includes: non-financial support. Merryn Voysey, Maheshi Ramasamy, Katherine Emary, Andrew Pollard has patent licensed to AstraZeneca. The COV002 study was funded by UK Research and Innovation, National Institute for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca. This report is independent research funded by the UK NIHR and UK Research and Innovation., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Globally, there has been a commitment to produce and distribute a vaccine within 100 days of the next pandemic. This 100-day target will place pressure on countries to make swift decisions on how to optimise vaccine delivery. We used data from the COVID-19 pandemic to inform mathematical modelling of future pandemics in Indonesia for a wide range of pandemic characteristics. We explored the benefits of vaccination programs with different start dates, rollout capacity, and age-specific prioritisation within a year of the detection of a novel pathogen. Early vaccine availability, public uptake of vaccines, and capacity for consistent vaccine delivery were the key factors influencing vaccine benefit. Monitoring age-specific severity will be essential for optimising vaccine benefit. Our study complements existing pathogen-specific pandemic preparedness plans and contributes a tool for the rapid assessment of future threats in Indonesia and similar middle-income countries., Competing Interests: Declaration of competing interest The authors declare that they have no competing financial interests or personal relationships that influenced the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Healthcare workers (HCWs) are recommended to receive at least three spike-antigen exposures to generate basic immunity and to mediate herd protection of vulnerable patients. So far, less attention has been put on the cellular immune response induced by homologous (three BTN162b2mRNA doses) or heterologous (mRNA-1273 as third dose building on two BTN162bmRNA doses) and the immunological impact of breakthrough infections (BTIs). Therefore, in 356 vaccinated HCWs with or without BTIs the Anti-SARS-CoV-2-Spike-IgG concentrations and avidities and B- and T-cell-reactivity against SARS-CoV-2-Spike-S1- and Nucleocapsid-antigens were assessed with Interferon-gamma-ELISpot and by flow-cytometry. HCWs who had hybrid immunity due to BTIs exhibited strong T-cell-reactivity against the Spike-S1-antigen. A lasso regression model revealed a significant reduction in T-cell immune responses among smokers (p < 0.0001), with less significant impact observed for age, sex, heterologous vaccination, body-mass-index, Anti-Nucleocapsid T-cell reactivity, days since last COVID-19-immunization, and Anti-SARS-CoV-2-Spike-IgG. Although subgroup analysis revealed higher Anti-SARS-CoV-2-Spike-IgG after heterologous vaccination, similar cellular reactivity and percentages of Spike-reactive T- and B-cells were found between homologous and heterologous vaccination. Anti-SARS-CoV-2-Spike-IgG concentrations and avidity significantly correlated with activated T-cells. CD4 + and CD8 + responses correlated with each other. A strong long-term cellular immune response should be considered as baseline for recommendations of booster doses in HCWs with prioritization of smokers. HCWs presented significant T-cellular reactivity towards Spike-S1-antigen with particularly strong responses in hybrid immunized HCWs who had BTIs. HCWs without BTI presented similar percentages of Spike-specific B- and T-cells between homologous or heterologous vaccination indicating similar immunogenicity for both mRNA vaccines, BNT162b2mRNA and mRNA-1273., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Martina Prelog received honoraria for presentations at scientific meetings from Abbvie, BioNTech, Chugai-Roche, Doctorflix, GSK, Esanum, Janssen, Novartis, Moderna, MSD, Pfizer, Sanofi and SOBI, received honoraria for advisory boards from Abbvie, BioNTech, GSK, Janssen, Moderna, Novartis, and Pfizer , received travel scholarships from Chugai-Roche, GSK, Novartis and Pfizer, received financial support for conduction of investigator-initiated research from Baxter, Chugai-Roche, Galapagos,  GSK, Moderna, Novartis, MSD, Pfizer and SOBI; Martina Prelog declares to have no conflict of interest regarding the manuscript.  Manuel Krone receives honoraria from GSK and Pfizer outside the submitted work. All other authors declare no potential conflicts of interest. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

At present, mRNA-based vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are being administered on a global scale. While the efficacy of mRNA vaccines has been demonstrated, several unknowns remains. For example, as the number of booster vaccinations increases, there are uncertainties regarding how long effects of a vaccine will last and how much individual variability exists. In this study, to predict the duration of vaccine efficacy, we modeled the kinetics of antibody levels for each SARS-CoV-2 vaccination dose, incorporating predictive intervals to estimate the duration of vaccine efficacy and to account for variability among individuals. A total of 3,059 serum samples from 1,346 participants were assayed to quantify IgG antibodies specific for the S1 subunit of the S protein (anti-S1 IgG) and neutralizing antibody activities against SARS-CoV-2. A power law model was used to simulate the decay of antibody titers following vaccination, and models were constructed to assess antibody level kinetics after the second, third, fourth, and fifth vaccinations. The models assumed that booster vaccinations would significantly reduce the decline in anti-S antibody and neutralizing antibody levels, resulting in levels being maintained for a longer period. No significant differences in the decay rate of antibody levels were observed among age groups, yet the peak titers of antibody levels were significantly higher in the ≤ 39 age group than in the ≥ 60 age group following the second vaccination; these differences were not observed after the third and fourth vaccinations. The modeling of antibody level kinetics after vaccination is considered to be useful for understanding the immune status of mRNA vaccine recipients., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Numerous vaccine candidates have emerged in the fight against SARS-CoV-2, yet the challenges posed by viral evolution and the evasion of vaccine-induced immunity persist. The development of broadly protective vaccines is essential in countering the threat posed by variants of concern (VoC) capable of eluding existing vaccine defenses. Among the diverse SARS-CoV-2 vaccine candidates, detailed characterization of those based on the expression of the entire spike protein in mammalian cells have been limited. In our study, we engineered a recombinant prefusion-stabilized trimeric spike protein antigen, IMT-CVAX, encoded by the IMT-C20 gene. This antigen was expressed utilizing a suspension mammalian cell line (CHO-S). The establishment of a stable cell line expressing IMT-CVAX involved the integration of the gene into the CHO genome, followed by the expression, purification, and characterization of the protein. To gauge the vaccine potential of adjuvanted IMT-CVAX, we conducted assessments in small animals. Analyses of blood collected from immunized animals included measurements of anti-spike IgG, SARS-CoV-2 neutralization, and responses from GC-B and T fh cells. Furthermore, the protective efficacy of IMT-CVAX was evaluated using a Hamster challenge model. Our findings indicate that adjuvanted IMT-CVAX elicits an excellent immune response in both mice and hamsters. Notably, sera from animals immunized with IMT-CVAX effectively neutralize a diverse range of SARS-CoV-2 variants. Moreover, IMT-CVAX immunization conferred complete protection to hamsters against SARS-CoV-2 infection. In hACE2 transgenic mice, IMT-CVAX vaccination induced a robust response from GC-B and T fh cells. Based on our preclinical model assessments, adjuvanted IMT-CVAX emerges as a highly efficacious vaccine candidate. This protein-subunit-based vaccine exhibits promise for clinical development, offering an affordable solution for both primary and heterologous immunization against SARS-CoV-2 variants., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ravi PN Mishra has patent #PROCESS FOR RECOMBINANT PRODUCTION OF SARS-COV-2 SPIKE PROTEIN pending to NA. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Purpose: The prevalence of recommendation of human papillomavirus (HPV) vaccination by health care providers has improved over the last decade. However, research to determine whether the COVID-19 pandemic affected the progress in recommendation among adolescents across the U.S. regions has been limited. Therefore, the present study was conducted to determine if region was associated with provider recommendation of HPV vaccines in 2019-2021 and whether changes in recommendations varied by region., Method: Using a cross-sectional design to examine National Immunization Survey-Teen (2019-2021) data, logistic regression and moderation analyses were performed to model region variation in HPV vaccine recommendations (n = 50,739 respondents)., Results: The odds of recommendation were higher in the Midwest (aOR, 1.17 [95% CI, 1.06-1.29]), and Northeast (aOR, 1.38 [95% CI, 1.23-1.56]) regions than in the South region. Also, the odds of provider recommendation were higher in 2020 (aOR,1.16 [95% CI, 1.03-1.30]) than in 2019. Other variables-sex, age, race/ethnicity, health insurance status, and poverty status-were associated with recommendation of HPV vaccination., Conclusion: Although the improvement in recommendation from 2019 to 2020 is an important public health gain, recommendation in the South still lags behind that in other regions. More efforts are needed to improve HPV vaccination recommendations in this region., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Pneumonia is one of the main contributors to non-cancer mortality among patients with head and neck cancer (HNC). This study aimed to determine the vaccine uptake for pneumococcal polysaccharide and conjugate vaccines, quadrivalent influenza vaccines, and mRNA COVID-19 vaccines before and after an HNC diagnosis. Furthermore, the study investigated the timing of vaccination after a cancer diagnosis., Materials & Methods: This register based multicentre study included Danish patients ≥ 18y diagnosed with HNC between 2018 and 2021. The vaccine uptake was assessed by calculating cumulative incidence (CI), while the timing of vaccination after an HNC diagnosis was explored by calculating incidence rates of vaccination the first and second half year after a cancer diagnosis., Results: The cumulative incidence of vaccine uptake for pneumococcal vaccines was estimated to be 8 % and 16 % one year before and after an HNC diagnosis, respectively. The CIs were 36 % and 38 % for quadrivalent influenza vaccines, respectively, whereas the CIs of vaccine uptake for mRNA COVID-19 vaccines were 60 % and 89 %. The IR of mRNA COVID-19 vaccinations the first half year after HNC diagnosis were 273 per 1000 person-months of follow-up (PMFU) and 111 per 1000 PMFU the second half year, respectively (IRR: 0.38, p < 0.001). Comparing the same periods, the IR of quadrivalent influenza vaccination was 28 per 1000 PMFU and 51 per 1000 PMFU (IRR: 1.95, 0 < 0.001). The IRs of pneumococcal vaccinations were 11 per 1000 PMFU and 14 per 1000 PMFU (IRR 1.28, p = 0.21)., Conclusions: Although our study shows a significant increase in pneumococcal and COVID-19 vaccine uptake after HNC diagnosis, a gap remains in vaccine uptake before diagnosis, underscoring the need for increased awareness of vaccination options and recommendations. Our findings could serve as a reference for future recommendations., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Mads Frederik Eiberg reports financial support was provided by Danish Cancer Society. Zitta Barrella Harboe reports financial support was provided by Independent Research Fund Denmark. Zitta Barrella Harboe reports financial support was provided by Lundbeck Foundation. Zitta Barrella Harboe reports financial support was provided by Danish Cancer Society. Omid Rezahosseini reports financial support was provided by A.P. Møllers fonden. Omid Rezahosseini reports financial support was provided by Research Foundation of Rigshospitalet. Zitta Barrella Harboe reports a relationship with The Danish Vaccination Council that includes: board membership. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The emergence and ongoing evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has highlighted the need for rapid vaccine development platforms that can be updated to counteract emerging variants of currently circulating and future emerging coronaviruses. Here we report the development of a "train model" subunit vaccine platform that contains a SARS-CoV-2 Wuhan S1 protein (the "engine") linked to a series of flexible receptor binding domains (RBDs; the "cars") derived from SARS-CoV-2 variants of concern (VOCs). We demonstrate that these linked subunit vaccines when combined with Sepivac SWE™, a squalene in water emulsion (SWE) adjuvant, are immunogenic in Syrian hamsters and subsequently provide protection from infection with SARS-CoV-2 VOCs Omicron (BA.1), Delta, and Beta. Importantly, the bivalent and trivalent vaccine candidates offered protection against some heterologous SARS-CoV-2 VOCs that were not included in the vaccine design, demonstrating the potential for broad protection against a range of different VOCs. Furthermore, these formulated vaccine candidates were stable at 2-8 °C for up to 13 months post-formulation, highlighting their utility in low-resource settings. Indeed, our vaccine platform will enable the development of safe and broadly protective vaccines against emerging betacoronaviruses that pose a significant health risk for humans and agricultural animals., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Arinjay Banerjee reports a relationship with Canadian Institutes of Health Research that includes: funding grants. Trina Racine reports a relationship with Coalition for Epidemic Preparedness Innovations that includes: funding grants. Darryl Falzarano reports a relationship with Canadian Institutes of Health Research that includes: funding grants. Arinjay Banerjee, Qiang Liu, Darryl Falzarano has patent fusion polypeptides, immunogenic compositions, methods and uses thereof pending to VIDO, University of Saskatchewan. The findings from this study have led to a patent application: fusion polypeptides, immunogenic compositions, methods and uses thereof. USPTO Patent application, United States of America. USPTO Patent application #63/452,586 (March 16, 2023). The authors declare no other conflict of interest. Morgane Joessel, Falko Apel, Thomas Courant, and Nicolas Collin from VFI used their trademarked Sepivac SWE™, a squalene in water emulsion (SWE) adjuvant in this study to formulate the vaccine candidates. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.]., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: COVID-19 vaccines were rolled out in South Africa beginning in February 2021. In this study we retrospectively assessed the cost-effectiveness of the vaccination programme in its first two years of implementation., Method: We modelled the costs, expressed in 2021 US$, and health outcomes of the COVID-19 vaccination programme compared to a no vaccination programme scenario. The study was conducted from a public payer's perspective over two time-horizons - nine months (February to November 2021) and twenty-four months (February 2021 to January 2023). Health outcomes were estimated from a disease transmission model parameterised with data on COVID-19-related hospitalisations and deaths and were converted to disability adjusted life years (DALYs). Deterministic and probabilistic sensitivity analyses (DSA and PSA) were conducted to assess parameter uncertainty., Results: Incremental cost-effectiveness ratio (ICER) was estimated at US$1600 per DALY averted during the first study time horizon. The corresponding ICER for the second study period was estimated at US$1300 per DALY averted. When 85% of all excess deaths during these periods were included in the analysis, ICERs in the first and second study periods were estimated at US$1070 and US$660 per DALY averted, respectively. In the PSA, almost 100% of simulations fell below the estimated opportunity cost-based cost-effectiveness threshold for South Africa (US$2300 DALYs averted). COVID-19 vaccination programme cost per dose had the greatest impact on the ICERs., Conclusion: Our findings suggest that South Africa's COVID-19 vaccination programme represented good value for money in the first two years of rollout., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: Vaccine hesitancy (VH) has been a major contributor to large outbreaks of vaccine-preventable diseases globally, including in the United States., Methods: Data from the 2019-2022 National Immunization Surveys were analyzed to assess parental hesitancy toward routine vaccination of their children aged 6 months -17 years. Joinpoint regression was employed to investigate trends in VH from 2019 to 2022 nationally overall and among socio-demographic subgroups. Using logistic regression, the difference between the prevalence of VH before and after the authorization of the COVID-19 vaccine for children aged 6 months-4 years, 5-11 years, and 12-17 years was computed. Both unadjusted and adjusted estimates were reported. VH was also compared within each socio-demographic subgroup with a reference level, at two-time points- before and after the authorization of the COVID-19 vaccine for each age group., Results: Overall, VH remained around 19.0 % from Q2 2019 to Q3 2022. Parents of non-Hispanic Black children had the largest average quarterly decrease in VH (β = -0.55; p < 0.05 by test for trend). After the authorization of the COVID-19 vaccine for children aged 6 months to 4 years, the adjusted percentage of children having parents that reported VH decreased by 2.2 (95 % CI: -3.9, -0.6) percentage points (pp) from 21.6 % to 19.4 %. Conversely, for children aged 5-11 years, VH increased by 1.2 (95 % CI: 0.2, 2.3) pp, from 19.8 % to 21.0 %. VH among parents of non-Hispanic Black children decreased after the authorization of the COVID-19 vaccine for adolescents aged 12-17 years but remained significantly higher compared to parents of non-Hispanic White children before and after authorization of the COVID-19 vaccine for all age groups., Discussion: About 1 in 5 children had parents reporting VH from 2019 to 2022. Parental VH increased after the authorization of the COVID-19 vaccine for children aged 5-11 years and declined for children aged 6 months-4 years., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The COVID-19 pandemic is over but the highly immunized or naturally exposed global population still requires booster vaccinations against newly emerging SARS-CoV-2 variants. We assessed safety and immunogenicity of booster doses of COVID-19 vaccines based on three different platforms in a setting that mimics the current routine practice in Brazil., Methods: In this phase 3 study from 14 February 2023 to 12 June 2023 we enrolled previously immunized adults to receive an additional booster dose of one of three vaccines. Immunogenicity against ancestor SARS-CoV-2 and Omicron BF.7, BQ.1.1.3, and XBB.1.5.6 sub-lineages was measured as ELISA IgG or virus neutralizing (VNT) antibodies and safety/reactogenicity assessed using diary cards., Results: Volunteers with a history of full primary COVID-19 immunization striated to three cohorts according to their previous booster vaccination history-0 (n = 26), 1 (n = 140) or 2 (n = 606) booster vaccinations-were randomized 2:1:1 to receive either recombinant protein (SCB-2019, Clover), adenovirus-vector (ChAdOx1-S, AstraZeneca/Fiocruz), or mRNA (BNT162b2, Pfizer/Wyeth). Baseline antibody titers were higher in individuals who had received one or two boosters and titers against both ancestor and Omicron sub-lineages increased in all groups regardless of the number of previous booster doses or the vaccine used. Day 28 geometric mean titers (GMTs) and geometric mean-fold rises (GMFR) against all variants were higher after BNT162b than SCB-2019 or ChAdOx1-S, but BNT162b groups displayed more rapid antibody waning at Day 84. Within cohorts each vaccine elicited similar GMFR against the different SARS-CoV-2 strains. All vaccines were well tolerated with similar solicited reactogenicity profiles., Conclusions: Protein, adenovirus-vector or mRNA vaccine boosters were equally well tolerated and immunogenic against ancestor SARS-CoV-2 and Omicron sub-lineages in fully primed adults with 0-2 prior boosters. BNT162b induced the highest immune responses but also the most rapid waning of antibodies 3 months after vaccination., Clinical Trial Registration: ClinicalTrials.gov, identifier NCT05812586., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Sue Ann Costa Clemens reports financial support was provided by Bill & Melinda Gates Foundation. Igor Smolenov reports a relationship with Clover Pharmaceuticals Inc. that includes: employment and equity or stocks. Ralf Clemens reports a relationship with Clover Pharmaceuticals Inc. that includes: board membership. Sue Ann Costa Clemens is a Professor in Global Health, Department of Paediatric Infectious Diseases, Oxford University, UK, Head of the Institute for Global Health, University of Siena, Italy, Director Vaccine Group Oxford-Brazil, and Senior Adviser at the Bill & Melinda Gates Foundation (BMGF) and member of the Scientific Advisory Board of various vaccine organizations including Clover Biopharmaceuticals Inc. Igor Smolenov was a full-time employee of Clover Biopharmaceuticals at the time of the study. Ralf Clemens is a Senior Advisor to BMGF and member of the Board of Trustees of the International Vaccines Institute (IVI) and member or chair of various vaccine companies including Clover Biopharmaceuticals Inc. Eveline P. Milan and Lily Weckx have no conflicts to declare. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: Although COVID-19 vaccine safety in 5-11-year-old children has been documented, half of Ontarian children this age remain unvaccinated. This study aimed to assess caregivers' vaccine acceptance for 5-11-year-old children and identify factors associated with vaccine non-acceptance., Methods: A multi-language self-administered survey was sent to caregivers of 5-11-year-old children through schools and community health centers within the Greater Toronto Area from April-July 2022. Sociodemographic characteristics and immunization behaviours were collected for caregivers, their 5-11-year-old children, and any older siblings. The primary outcome, COVID-19 vaccine acceptance, was previous uptake of COVID-19 vaccine or caregiver intent to vaccinate for their 5-11-year-old child. Data were analyzed using descriptive statistics and multivariable logistic regression., Results: In total, 807 caregivers were included in analysis. Although 93 % of caregivers had received two doses of COVID-19 vaccine, 77 % had a 5-11-year-old child who received at least one dose of vaccine. Caregivers age was associated with vaccine acceptance (vs. < 40 years; adjusted odds ratio [aOR] 2.1, 95 % confidence interval [CI] 1.4-3.1 for ages 40-49; aOR 2.8, 95 % CI 1.1-7.1 for ages ≥50 years). Immunization factors associated with vaccine acceptance included caregiver COVID-19 vaccination (aOR 38.1 vs. unvaccinated caregivers; 95 % CI 15.8-92.3), older siblings COVID-19 vaccination (aOR 49.2 vs. unvaccinated siblings; 95 % CI 18.3-132.3), and recent influenza vaccination for the child (aOR 6.9 vs. no influenza vaccine; 95 % CI 4.6-10.5). Among 189 caregivers with unvaccinated 5-11-year-old children, the most common reasons for non-acceptance were concerns about long-term side effects (59 %), lack of experience vaccinating children (41 %), and concerns that vaccines were developed too quickly (39 %)., Conclusion: Acceptance of COVID-19 vaccination for 5-11-year-old children were associated with caregiver vaccine behaviors and sociodemographic factors. These findings highlight groups of caregivers that can be targeted for educational interventions and concerns that may be addressed to increase vaccine confidence., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Shaun K. Morris reports a relationship with GlaxoSmithKline that includes: speaking and lecture fees. Shaun K. Morris reports a relationship with BioMerieux that includes: speaking and lecture fees. Shaun K. Morris reports a relationship with Pfizer that includes: consulting or advisory and funding grants. Shaun K. Morris reports a relationship with Merck that includes: consulting or advisory. Shaun K. Morris reports a relationship with Sanofi Pasteur that includes: consulting or advisory. Shaun K. Morris reports a relationship with Apotex that includes: consulting or advisory. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Aim: From the perspective of doctor-patient communication, this research used multiple methods combined natural language processing (NLP), a cross-sectional survey and an online experiment to investigated how risk perception influenced people's vaccination intention., Methods: In Study 1, we used Python to crawl 335,045 comments about COVID-19 vaccine published in a social media platform Sina Weibo (equivalent of Twitter in China) from 31 December 2020 to 31 December 2021. Text analysis and sentiment analysis was used to examine how vaccination intention, as measured by linguistic features from the LIWC dictionary, changed with individuals' perceptions of pandemic risk. In Study 2, we adopted a cross-sectional questionnaire survey to further test the relation of risk perception, vaccination intention, trust in physicians, and perceived medical recommendations in a Chinese sample (n = 386). In Study 3, we conducted an online experiment where we recruited 127 participants with high trust in physicians and 127 participants with low trust, and subsequently randomly allocated them into one of three conditions: control, rational recommendation, or perceptual recommendation., Results: Text and sentiment analysis revealed that the use of negative words towards COVID-19 vaccine had a significant decrease at high (vs. low) risk perception level time (Study 1). Trust in physicians mediated the effect of risk perception on vaccination intention and this effect was reinforced for participants with low (vs. high) level of perceived medical recommendation (Study 2), especially for the rational (vs. perceptual) recommendation condition (Study 3)., Conclusion: Risk perception increased vaccination intention through the mediating effect of trust in physicians and the moderating effect of perceived medical recommendations. Rational (vs. perceptual) recommendation is more effective in increasing intention to get vaccinated in people with low trust in physicians., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

In autumn 2023, European vaccination campaigns predominantly administered XBB.1.5 vaccine. In a European multicentre study, we estimated 2023 COVID-19 vaccine effectiveness (VE) against laboratory-confirmed symptomatic infection at primary care level between September 2023 and January 2024. Using a test-negative case-control design, we estimated VE in the target group for COVID-19 vaccination overall and by time since vaccination. We included 1057 cases and 4397 controls. Vaccine effectiveness was 40 % (95 % CI: 26-53 %) overall, 48 % (95 % CI: 31-61 %) among those vaccinated < 6 weeks of onset and 29 % (95 % CI: 3-49 %) at 6-14 weeks. Our results suggest that COVID-19 vaccines administered to target groups during the autumn 2023 campaigns showed clinically significant effectiveness against laboratory-confirmed, medically attended symptomatic SARS-CoV-2 infection in the 3 months following vaccination. A longer study period will allow for further variant-specific COVID-19 VE estimates, better understanding decline in VE and informing booster administration policies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: This study aimed to evaluate the effectiveness of SARS-CoV-2 mRNA vaccines in preventing infection and hospitalization among healthcare workers (HCWs) in the Valencian Community (Spain), considering vaccination timing, dose number, and predominant variant., Methods: A test-negative case-control design estimated vaccine effectiveness against symptomatic disease and hospitalization due to SARS-CoV-2. HCWs who underwent PCR or antigen testing for SARS-CoV-2 from January 2021 to March 2022 were included. Cases had a positive diagnostic test, while controls had negative tests. Adjusted vaccine effectiveness (aVE) was calculated using the formula: aVE = (1 - Odds ratio) × 100., Results: During the Delta variant's predominance, aVE against infection within 12-120 days post-second dose was 64.8 % (BNT162b2) and 59.4 % (mRNA-1273), declining to 21.2 % and 42.2 %, respectively, after 120 days. For the Omicron variant, aVE within 12-120 days post-second dose was 61.1 % (BNT162b2) and 85.1 % (mRNA-1273), decreasing to 36.7 % and 24.9 %, respectively, after 120 days. After a booster dose of mRNA-1273, aVE was 64.0 % (BNT162b2 recipients) and 65.9 % (initial mRNA-1273 recipients). Regardless of variant, aVE for hospitalization prevention after 2 doses was 87.0 % (BNT162b2) and 89.0 % (mRNA-1273)., Conclusion: The administration of two doses of Moderna-mRNA-1273 against SARS-CoV-2 in HCWs proved to be highly effective in preventing infections and hospitalizations in the first 120 days after the second dose during the predominance of the Omicron variant. The decline in VE after 120 days since the administration of the second dose was significantly restored by the booster dose administration. This increase in VE was greater for the Pfizer vaccine. COVID-19 hospitalization prevention remained stable with both mRNA vaccines throughout the study period., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Introduction: The long-term impact of initial immunogenicity induced by different primary COVID-19 vaccine series remains unclear., Methods: A prospective cohort study was conducted at 10 tertiary hospitals in Korea from March 2021 to September 2022. Immunogenicity assessments included anti-spike protein antibody (Sab), SARS-CoV-2-specific interferon-gamma releasing assay (IGRA), and multiplex cytokine assays for spike protein-stimulated plasma. Spike proteins derived from wild-type SARS-CoV-2 and alpha variant (Spike 1 ) and beta and gamma variant (Spike 2 ) were utilized., Results: A total of 235 healthcare workers who had received a two-dose primary vaccine series of either ChAdOx1 or BNT162b2, followed by a third booster dose of BNT162b2 (166 in the ChAdOx1/ChAdOx1/BNT162b2 (CCB) group and 69 in the BNT162b2/BNT162b2/BNT162b2 (BBB) group, based on the vaccine series) were included. Following the primary vaccine series, the BBB group exhibited significantly higher increases in Sab levels, IGRA responses, and multiple cytokines (CCL2/MCP-1, CCL3/MIP-1α, CCL4/MIP-1β, interleukin (IL)-1ra, IFN-γ, IL-2, IL-4, and IL-10) compared to the CCB group (all P < 0.05). One month after the third BNT162b2 booster, the CCB group showed Sab levels comparable to those of the BBB group, and both groups exhibited lower levels after six months without breakthrough infections (BIs). However, among those who experienced BA.1/2 BIs after the third booster, Sab levels increased significantly more in the BBB group than in the CCB group (P < 0.001). IGRA responses to both Spike 1 and Spike 2 proteins were significantly stronger in the BBB group than the CCB group after the third booster, while only the Spike 2 response were higher after BIs (P = 0.007). The BBB group exhibited stronger enhancement of T-cell cytokines (IL-2, IL-4, and IL-17A) after BIs than in the CCB group (P < 0.05)., Conclusion: Differences in immunogenicity induced by the two primary vaccine series persisted, modulated by subsequent booster vaccinations and BIs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

To assess the levels of and neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its mutants in serum samples from patients with breakthrough infection. Sixty-four patients with breakthrough infections were recruited for this cross-sectional study. All samples were used to neutralizing antibodies (nAbs) against SARS-CoV-2 and its mutants using a focused reduction neutralization assay. A total of 512 serum samples were obtained from unvaccinated patients who received one dose of vaccine (n = 12), received two doses of vaccine (n = 15), and received three doses of vaccine (n = 37). The geometric mean titer (GMT) of neutralizing antibodies against the Omicron subvariant was significantly lower (GMT 66.8 and 56.1) compared to the original strain, regardless of whether two or three doses of vaccine were administered. This result highlights that sera from breakthrough infections induce broad neutralization, but Omicron XBB.1.16 exhibits high immune evasion potential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Case-control studies involving test-negative (TN) and syndrome-negative (SN) controls are reliable for evaluating influenza and rotavirus vaccine effectiveness (VE) during a random vaccination process. However, there is no empirical evidence regarding the impact in real-world mass vaccination campaigns against SARS-CoV-2 using TN and SN controls., Objective: To compare in the same population the effectiveness of SARS-CoV-2 vaccination on COVID-19-related hospitalization rates across a cohort design, TN and SN designs., Method: We conducted an unmatched population-based cohort, TN and SN case-control designs linking data from four data sources (public primary healthcare system, hospitalization registers, epidemiological surveillance systems and the national immunization program) in a Chilean municipality (Rancagua) between March 1, 2021 and August 31, 2021. The outcome was COVID-19-related hospitalization. To ensure sufficient sample size in the unexposed group, completion of follow-up in the cohort design, and sufficient time between vaccination and hospitalization in the case-control design, VE was estimated comparing 8-week periods for each individual., Results: Among the 191,505 individuals registered in the primary healthcare system of Rancagua in Chile on March 1, 2021; 116,453 met the cohort study's inclusion criteria. Of the 9,471 hospitalizations registered during the study period in the same place, 526 were COVID-19 cases, 108 were TN controls, and 1,628 were SN controls. For any vaccine product, the age- and sex-adjusted vaccine effectiveness comparing fully and nonvaccinated individuals was 67.2 (55.7-76.3) in the cohort design, whereas it was 67.8 (44.1-81.4) and 77.9 (70.2-83.8) in the TN and SN control designs, respectively., Conclusion: The VE of a COVID-19 vaccination program based on age and risk groups tended to differ across the three observational study designs. The SN case-control design may be an efficient option for evaluating COVID-19 VE in real-world settings., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: A large vaccination campaign was initiated worldwide in December 2020 in order to prevent infection with SARS-CoV-2 and severe Covid-19 disease. However, long-term adverse effects of vaccination remain unclear. Therefore, our objective was to examine the association between vaccination and the incidence of autoimmune diagnoses in the first year after vaccine uptake., Methods: This retrospective cohort study based on Clalit Health Services (CHS) comprehensive database compared the rates of immune-mediated diagnoses among BNT162b2 vaccinated versus unvaccinated individuals. As a reference, a secondary cohort compared individuals infected with Sars-CoV-2 versus uninfected individuals. The minimum follow-up period was 4 months. The cohorts were divided into 4 age groups (12-17, 18-44, 45-64, 65 years or older). Multivariate Cox proportional hazard regression models were applied, followed by a correction for multiple comparisons using the False Discovery Rate (FDR) method, hence accounting for the investigation of multiple clinical outcomes., Results: Increased risk for immune-mediated diagnoses following vaccination with BNT162b2 was observed for psoriasis in all age groups (HR 1.41-1.69), colitis among patients younger than 65 years (HR 1.38-1.93), vitiligo in patients aged 45-64 (HR 2.82, 95 %CI: 1.57-5.08) and for polymyalgia-rheumatica in patients aged 65 years or older (HR 2.12, 95 % CI: 1.3-3.47). In the reference cohort, patients who were infected by Covid-19 were at increased risk for fibromyalgia (HR 1.72, 95 % CI: 1.36-2.19 in individuals aged 18-44; HR 1.71, 95 % CI: 1.31-2.22 in individuals aged 45-64), and hypothyroidism (HR 1.54, 95 % CI: 1.15-2.07 in individuals aged 65 years or older)., Conclusions: The BNT162b2 vaccine was associated with increased risk (though rare) for psoriasis, colitis and polymyalgia rheumatica. These findings should be considered as a part of the risk-benefit assessment when planning future vaccination programs for various population groups., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Clinical trials of new vaccines based on existing variants of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) are often impacted by the emergence of new virus variants. We evaluated the efficacy, immunogenicity, and safety of S-268019-b, a recombinant spike protein subunit vaccine based on the ancestral strain, for preventing symptomatic coronavirus disease 2019 (COVID-19) during the Omicron (BA.2)-dominant period in Vietnam. In this multicentre, phase 3, randomised (2:1), observer-blind, placebo-controlled crossover study, participants received 2 intramuscular doses (28 days apart) of either 10 µg of S-268019-b (Recombinant S-protein vaccine) or placebo. The primary endpoint was incidence of laboratory-confirmed symptomatic COVID-19 before crossover, with onset within 14 days following the second dose, in participants who were seronegative and reverse transcription polymerase chain reaction (RT-PCR)-negative at baseline. The secondary endpoints included immunogenicity and safety. In total, 8,594 participants were randomised (S-268019-b [n = 5,727]; placebo [n = 2,867]). Vaccine efficacy versus placebo was 39·1 % (95 % confidence interval [CI]:26·6-49·5; one-sided P = 0·0723). The incidence rate (95 % CI) of symptomatic COVID-19 was 776·41/1,000 person-years (682·04-880·19) in the S-268019-b group and 1272·87/1,000 person-years (1101·32-1463·57) in the placebo group. The geometric mean titres (95 % CI) of the SARS-CoV-2 neutralising antibody increased on Day 57 versus baseline with S-268019-b (34·66 [27·04-44·41] versus 2·50 (non-estimable) but not with placebo. There were no safety concerns regarding S-268019-b. S-268019-b did not demonstrate the targeted efficacy threshold against symptomatic COVID-19; however, findings were comparable with other prophylactic vaccines based on ancestor strain during the Omicron-dominant period. S-268019-b demonstrated immunogenicity and was well-tolerated. ClinicalTrials.gov identifier: NCT05212948., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Vu Dinh Thiem reports financial support was provided by Shionogi & Co., Ltd. Andrew J Pollard reports financial support was provided by Gates Foundation, Wellcome Trust, Cepi, MRC, NIHR, Serum Institute of India, Astra Zeneca, and EC. Andrew J. Pollard reports financial support was provided by Shionogi and Co Ltd. Akari Kamitani reports a relationship with Shionogi and Co Ltd that includes: employment. Yukio Tada reports a relationship with Shionogi and Co Ltd that includes: employment and equity or stocks. Hidenori Fukuyama reports a relationship with Shionogi and Co Ltd that includes: employment. Yuka Iwasaki reports a relationship with Shionogi and Co Ltd that includes: employment. Mari Ariyasu reports a relationship with Shionogi and Co Ltd that includes: employment. Takuhiro Sonoyama reports a relationship with Shionogi and Co Ltd that includes: employment and equity or stocks. Andrew J Pollard is a contributor to intellectual property licensed by Oxford University Innovation to AstraZeneca and was honorary Chair of DHSC’s Joint Committee on Vaccination and Immunisation and member of WHO’s SAGE until 2022. Pham Thi Van Anh, Chu Van Men, and Do Thai Hung have no conflicts to declare. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objectives: Trust in governments and public institutions as a determinant of public health outcomes has gained increased attention since the COVID-19 pandemic. Provided historically low confidence in vaccines in Japan, investigating the role of trust in information sources and actual COVID-19 vaccination uptake behavior will be invaluable for future vaccine promotion policymaking. Therefore, the objective of this study was to elucidate the determinants of COVID-19 vaccination uptake and evaluate the relationship between trust in different information sources and COVID-19 vaccination behavior in Japan., Methods: For this study, we leveraged a longitudinal series of web-based surveys of 19,174 individuals in Japan conducted between 2021 and 2022 which asked questions regarding a wide range of sociodemographic and psychographic characteristics related to the COVID-19 pandemic. Determinant analysis for vaccination (at least one dose of a COVID-19 vaccine) was conducted via multiple logistic regression, and odds ratios (OR) with 95% confidence intervals (CI) were estimated., Results: After adjustment for sociodemographic determinants of vaccine uptake, aggregate trust in the systems and institutions of vaccine approval (OR: 1.42, 95% CI: 1.30-1.56), and trust in information about the COVID-19 pandemic coming from government sources (OR: 1.27, 95% CI: 1.12-1.44) were found to be consistently powerful predictors of COVID-19 vaccination. Trust in media sources including traditional media (OR: 1.21, 95% CI: 1.07-1.36), and the internet (OR: 0.77, 95% CI: 0.66-0.89) had significant and opposing effects., Conclusions: Our findings support the broader hypothesis that trust in governments and public health institutions remains a powerful determinant for COVID-19 vaccine uptake in Japan. We also found that vaccination decision-making is a multifactorial process that includes the synthesis of trust in public institutions and media, and its interaction with psychosocial determinants such as prosociality and health literacy. We hope to apply this study's findings towards future vaccine programs for contagious diseases., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

In 2020-2021, all countries of the WHO Eastern Mediterranean Region [EMR] introduced COVID-19 vaccine with inequalities in coverage across countries. As for 2023, we reviewed subsequent progress in deployment, coverage, acceptance, and integration. As of 31 December 2023, coverage in EMR reached 51% for primary series and 19 % for the first booster, higher in high income countries (77 % and 44 %, respectively) than in upper middle-income countries (49 % and 20 %), Advance Market Commitment [AMC] non-Gavi eligible countries (47 % and 15 %) and AMC Gavi eligible countries (49 % and 16 %). Thirteen countries measured coverage among healthcare workers (76 % and 43 %, respectively) and 15 among elderly (69 % and 38 %, respectively). Three rounds of the regional Knowledge, Attitudes, and Practices [KAP] survey on COVID-19 vaccine acceptance in 2021-2022 indicated that acceptance increased from 20 % in June-July 2021 to 62 % in October-November 2021, and 77 % in June-July 2022. Those unvaccinated but intending to be vaccinated decreased from 60 % to 23 % and 11 %, respectively. Unvaccinated without intention to be vaccinated decreased from 15 % to 10 % and 11 %, respectively. Twenty out of 22 countries in the region had completely or partially integrated COVID-19 vaccination into the Expanded Programme on Immunization [EPI] and Primary Health Care [PHC]. Overall, challenges to reach high-risk groups persisted as the population was less concerned about Omicron variant of the SARS-CoV-2 virus. Countries should build on the trust, momentum, and lesson-learned generated from COVID-19 vaccination to get the highest risk groups vaccinated and switch from a time bound and project type approach to a sustainable and long-term approach for COVID-19 vaccine delivery that would be integrated into the routine EPI and PHC., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

With the continuous emergence of coronavirus disease 2019 (COVID-19) waves, the scientific community has developed a vaccine that offers broad-spectrum protection at virus-targeted organs for inhibiting the transmission and protection of disease development. In the present study, a bivalent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine containing receptor-binding domain (RBD) protein of spike from Wuhan-1 and omicron BA.1 loaded in nanoparticles, bivalent RBD NPs, was developed. The immunogenicity and protective efficacy of this vaccine candidate were evaluated using an in vivo model. Results showed that mice that received intranasal cGAMP-adjuvanted bivalent RBD-NPs vaccine elicited robust and durable antibody responses. The stimulated antibody broadly neutralized the ancestral strain and variants of concerns (delta and omicron BA.1) in the upper and lower respiratory tracts. Furthermore, the immunized mice developed T-cell response in their lung tissue. Importantly, intranasal immunization with this vaccine candidate efficiently protected mice from nasal infection caused by both Wuhan-1 and BA.1 viruses. Immunized mice that remained susceptible to nasal infection did not develop any symptoms. This is because activated responses in the nasal cavity significantly suppressed virus production. Another word is this nasal vaccine completely protected the mice from disease development and mortality. Therefore, the bivalent RBD vaccine platform has potential to be developed into an anti-SARS-CoV-2 universal vaccine., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Most studies examining factors associated with pediatric influenza (flu) and coronavirus disease (COVID-19) vaccination uptake focus on parental demographics. We examined whether the childhood cultural health environment (CHE) of parents (measured by self-reported regular attendance at doctor and dentist visits during childhood) was associated with flu and COVID-19 vaccination of their children. Using 2023 survey data from 397 US parents and causal inference methods, we estimated the average causal effect of parental CHE on flu vaccination rates (0.16 [95 % confidence interval: 0.06,0.27]) and COVID-19 (0.14 [95 % confidence interval: 0.04,0.24]), indicating that if all parents had attended regular doctor/dentist visits as children, flu and COVID-19 vaccination rates in children would be 16 % and 14 % higher, respectively, than if none had. Our findings suggest that early life exposure to medical and dental care has significant and lasting effects on the health of individuals and families., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier India Pvt Ltd. Published by Elsevier Ltd.. All rights reserved.)

Autonomous motivation is considered a powerful driver of health behaviour, but less is known about the specific roles played by basic needs. Drawing on the context of the COVID-19 pandemic, this research examined basic needs as a motivational determinant of vaccination. We hypothesized that satisfaction of basic needs (autonomy, competence, relatedness) has both a direct and an indirect effect (through trust in science and government) on vaccine hesitancy. Two studies (Study 1: N = 968 French and British; Study 2, pre-registered: N = 716 Americans) tested our hypotheses and compared vaccinated and non-vaccinated individuals using multigroup structural equation models. We found positive direct (in both studies) and indirect (in Study 1) effects of autonomy satisfaction on vaccine acceptance. In contrast, competence satisfaction was directly and indirectly, via science mistrust, related to vaccine hesitancy, particularly among non-vaccinated people. Competence satisfaction also indirectly reduced the intention to vaccinate in both studies. We found no impact of relatedness. Complementing previous work on self-determination theory, our research demonstrates the importance of considering the distinct roles of basic needs. Moreover, we highlight that increasing autonomy and science trust may be an efficient strategy to improve vaccine acceptance and vaccination, even among reluctant individuals., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Background: The association between covid-19 vaccine and menstrual disturbance is unclear., Methods: An in-person cross-sectional survey among female members ≥ 18 years enrolled in an ongoing Zero TB prospective cohort in Northern India who had received one or two doses of covid-19 vaccine was conducted to study the characteristics and association of menstrual disturbance within six months of receiving Covishield., Results: Between June 29 and September 5, 2021, 339 females ≥ 18 years of age were administered the survey. Median age was 30 (IQR: 22-39) years; 84 % were between 18 and 49 and 16 % were ≥ 50 years old. There were 152 college students, 27 healthcare workers, and 160 nuns. Forty-two women (12 %) had received one dose and 297 (88 %) had received two doses of Covishield. Overall, 66 (20 %) women reported experiencing menstrual disturbance after receiving Covishield vaccine. The problems included early menstruation: 6 % (n = 19/339); late menstruation: 4 % (n = 14/339); and heavier bleeding: 5 % (n = 17/339). Disturbances lasted for less than seven days and cycles normalized in 1-3 months. There was no post-menopausal bleeding. There was no significant difference in menstrual disturbance based on receiving one vs. two doses of Covishield (OR: 1.58; 95 % CI: 0.55-4.57; p = 0.381). History of SARS-CoV-2 infection was not associated with the development of menstrual disturbance among the vaccinees (OR: 0.63; 95 % CI: 0.24-1.73; p = 0.379). Presence of emotional disturbance at baseline (OR: 31; 95 % CI: 3.52-267; p = 0.002) or previous history of dysmenorrhea (OR: 41; 95 % CI: 8.7-196; p < 0.001) was associated with menstrual disturbance in the vaccinees, indicating their potential to confound or bias study results., Conclusion: Menstrual problems were reported by Covishield vaccinees, but they were minor and reversible within three months and do not constitute a ground for vaccine hesitancy. Studies designed to assess causal link taking care to avoid selection bias or confounding are needed., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: A single dose of Ad26.COV2.S is well-tolerated and effective in preventing moderate-to-severe disease outcomes due to COVID-19. We evaluated the impact of dose level, number of doses, and dose interval on immunogenicity, reactogenicity, and safety of Ad26.COV2.S in adults. Anamnestic responses were also explored., Methods: This randomised, double-blind, placebo-controlled, Phase 2a study was conducted in adults aged 18-55 years and ≥ 65 years (NCT04535453). Four dose levels (1.25 × 10 10 , 2.5 × 10 10 , 5 × 10 10 , and 1 × 10 11 viral particles [vp], single and 2-dose schedules, and dose intervals of 56 and 84 days, were assessed. Four or 6 months post-primary vaccination, Ad26.COV2.S 1.25 × 10 10 vp was given to evaluate anamnestic responses. Humoral and cell-mediated immune responses were measured. Reactogenicity and safety were assessed in all participants., Results: All Ad26.COV2.S schedules induced humoral responses with evidence of a dose response relationship. A single dose of Ad26.COV2.S (5 × 10 10 vp) induced antibody and cellular immune responses that persisted for up to at least 6 months. In the 2-dose regimens, antibody responses were higher than 1-dose regimens at comparable dose levels, and the magnitude of the immune response increased when the interval between doses was increased (84 days vs 56 days). Rapid, marked immune responses were observed in all groups after vaccine antigen exposure indicating immune memory. Durable immune responses were observed in all groups for up to at least 6 months post-antigen exposure. Strong and consistent correlations between neutralising and binding antibodies were observed CD4 + and CD8 + T cell responses were similar after all regimens. Reactogenicity within 7 days post-vaccination tended to be dose-related., Conclusion: The study supports the primary, single dose schedule with Ad26.COV2.S at 5 × 10 10 vp and homologous booster vaccination after a 6 month interval. Rapid and marked responses to vaccine antigen exposure indicate induction of immune memory by 1- and 2-dose primary vaccination., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Vicky Cardenas reports financial support was provided by Johnson & Johnson. Mathieu Le Gars reports financial support was provided by Johnson & Johnson. Carla Truyers reports financial support was provided by Johnson & Johnson. Javier Ruiz-Guinazu reports financial support was provided by Johnson & Johnson. Frank Struyf reports financial support was provided by Johnson & Johnson. Alicia Colfer reports financial support was provided by Johnson & Johnson. Macaya Douoguih reports financial support was provided by Johnson & Johnson. Jerald Sadoff reports financial support was provided by Johnson & Johnson. Marc Bonten reports a relationship with Shionogi, Merck, GSK and Janssen Vaccines that includes: consulting or advisory. Marc Bonten reports a relationship with Sanofi that includes: board membership. Frank Struyf reports a relationship with GSK that includes: equity or stocks. Marc Bonten reports a relationship with Johnson & Johnson, Merck, Sanofi that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Social events may provide important cues that influence the sense of reality, including the perception that conspiracy theories are plausible. Using longitudinal panel data collected in the UK from March 2020 to December 2021, this study aims to identify whether social events influenced the strength of the association between conspiracy mentality and vaccine intentions during the COVID-19 pandemic. Consistent with previous research, the conspiracy mentality was a significant predictor of vaccine intentions across three-time points, but also that conspiracy mentality measured in March 2020 predicted that participants were more hesitant to the vaccines in December 2020. The primary finding was that different social events moderated the strength of the correlation between conspiracy mentality and vaccine intentions within similar participants. Conspiracy mentality became more vital to evaluate COVID-19 vaccines in December 2020, when the vaccination program was about to commence., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

Long-COVID (having symptoms lasting 3 months or longer post-infection) is an emerging public health concern, yet research on whether COVID-19 booster vaccines can mitigate this condition is limited. This study examined associations between booster uptake and long-COVID prevalence among U.S. adults. Data were analyzed from 8757 adults aged 18 years or older with a history of COVID-19 infection from the 2022 National Health Interview Survey. Weighted prevalence and logistic regression models examined relationships between self-reported COVID-19 booster vaccination status and long-COVID, adjusting for sociodemographics and health factors. 19.5 % reported experiencing long-COVID. Individuals receiving the COVID-19 booster vaccine had significantly lower adjusted odds of long-COVID (OR 0.75, 95 % CI 0.61-0.93) compared to unvaccinated individuals. Overall, these findings suggest that COVID-19 booster vaccination is associated with a reduced prevalence of long-COVID among the U.S. adult population, underscoring the importance of optimizing booster uptake to mitigate the long-term impacts of COVID-19., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier India Pvt Ltd. Published by Elsevier Ltd.. All rights reserved.)

Objectives: To determine factors associated with intention to receive recommended COVID-19 booster vaccines in 2023-2024., Methods: A cross-sectional study of 1,256 individuals at Minnesota State and County fairs was conducted to assess their intention to receive a COVID-19 booster vaccine in the coming year if recommended. The association between booster intention and multiple factors believed to influence willingness to receive the vaccine, including perceived vaccine safety, perceived risk of COVID-19, public health knowledge, fear of future pandemics, and political affiliation, were analyzed using ordinal logistic regression and adjusted odds ratios (aOR)., Results: Intention to receive a COVID-19 booster vaccine was high among our participants with 56% reporting they were extremely likely to receive the vaccine this year and another 15% reporting that they were likely to do the same. A strong association with getting a booster vaccine was found between perceived vaccine safety (aOR: 15.3, 95% CI: 10.6-22.2), perceived COVID-19 risk (aOR: 3.5, 95% CI: 2.4-5.1), pandemic fear (aOR: 3.4, 95% CI: 2.4-4.8), public health knowledge (aOR: 1.3, 95% CI: 0.9-1.8), and democrat political affiliation (aOR: 2.8, 95%CI: 1.8-4.4)., Conclusions: Our study emphasizes the importance of perceived vaccine safety as a predictor of intention to accept COVID-19 vaccines and highlights the continued need to effectively communicate with the public about the safety of vaccines., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Background: The Recombinant Omicron BA.4/5-Delta COVID-19 Vaccine (ZF2202-A) is primarily designed for the Delta and Omicron BA.4/5 variants. Our objective was to assess the safety and immunogenicity of ZF2202-A in Chinese adults., Methods: A total of 450 participants aged ≥ 18 years, who had completed primary or booster vaccination with a COVID-19 vaccine more than 6 months prior, were enrolled in this randomized, double-blind, active-controlled trial. Participants in the study and control groups were administered one dose of ZF2202-A and ZF2001, respectively. Immunogenicity subgroups were established in each group., Results: At 14 days after vaccination, the seroconversion rates of Omicron BA.4/5, BF.7, and XBB.1 in the ZF2022-A group were 67.7 %, 58.6 %, and 62.6 %, with geometric mean titers (GMTs) of neutralizing antibodies at 350.2, 491.8, and 49.5, respectively. The main adverse reactions (ARs) were vaccination site pain, pruritus, fatigue, and asthenia in both the ZF2022-A group and ZF2001 group., Conclusions: The novel bivalent vaccine ZF2202-A demonstrated satisfactory immunogenicity and safety against Omicron variants as booster dose in adults with prior vaccination of COVID-19 vaccines., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: To estimate the number of avoidable COVID-19 deaths and hospitalizations in Brazil., Methods: Secondary data on COVID-19 deaths and hospitalizations were related to two measures of cumulative vaccine coverage (in the last six months and before this period) by negative binomial regression to estimate population-level protective effectiveness (PLPE) against severe disease. The latter includes the overall protective effect of all COVID-19-preventive measures, such as direct and indirect vaccine effectiveness, social distancing, and lockdown, but only the vaccine coverage data were available for the regression analysis., Results: COVID-19 mortality rates per 100,000 inhabitants were 10.26, 16.45, 0.14, and 0.94, for the years 2020, 2021, 2022, and the first half of 2023. In the same order and scale, COVID-19 hospitalization rates were 28.96, 47.04, 0.40, and 3.74. Both hospitalizations and deaths peaked early in 2021, then sharply reduced by the end of the year as the first-dose vaccine coverage reached 90 %, and rose with the vaccine coverage within the last six months falling below 10 % in 2023. PLPE for preventing COVID-19 deaths was 19.9 %, 98.9 %, and 93.1 % for the years 2021, 2022, and the first half of 2023. Had Brazil vaccinated the same number of people against COVID-19 in the last quarter of 2020 as it did in the first quarter of 2021, over 117,000 deaths and 277,000 hospitalizations could have been avoided over the period analyzed., Conclusions: PLPE reduction in 2023 was likely caused by low vaccine uptake. The disease burden could have been much lower had the vaccination started earlier and had the vaccine uptake not dropped so sharply in 2023., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Emil Kupek reports financial support was provided by National Council for Scientific and Technological Development. Emil Kupek reports a relationship with National Council for Scientific and Technological Development that includes: funding grants. The research was funded by the Brazilian Ministry of Science and Technology Development (acronym CNPq in Portuguese) grant number 303552/2022-0. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction: Vaccine mandates are controversial, and people vary widely in their preferences to support or reject vaccine mandates. For some, vaccine mandates represent a commitment to reduce harm and support public health. For others, vaccine mandates are viewed as a threat to individual freedom and a violation of personal choice. This manuscript investigated support for a COVID-19 vaccine mandate among COVID-19-vaccinated individuals and identified differences by demographic characteristics and COVID-19 experience., Methods: Cross-sectional surveys were given to COVID-19-vaccinated individuals at a vaccination clinic in South Texas in the U.S. with the goal of identifying attitudes, beliefs, and perceptions about COVID-19 vaccination and willingness to support a COVID-19 vaccination mandate. Associations of interest were analyzed using descriptive statistics., Key Results: Approximately half of the sample was of Hispanic or Latino origin (48 %); most respondents identified as White (59 %), followed by 12 % who identified as Asian. Overall, 59 % of participants supported the possibility for a COVID-19 vaccine mandate. Preliminary data showed significant racial differences in willingness to support a possible COVID-19 vaccine mandate (χ 2 (1, n = 893) = 26.7, p < .001, phi = .17); 80 % of Asian people reported support for COVID-19 vaccination mandate compared to 50 % to 57 % for other racial groups. Significant differences also emerged by ethnicity (χ 2 (4, n = 1033) = 7.12, p = .008, phi = .08) whereby a higher percentage of Latino participants (66 %) reported willingness to support a COVID-19 vaccine mandate. Similarly, significant differences were found by age (χ 2 (4, n = 1045) = 20.92, p < .001, phi = .21), yet no significant differences were found by sex or previous COVID-19 diagnosis., Conclusion: Support for a COVID-19 vaccination mandate is controversial even among vaccinated people. Identifying and understanding cultural and contextual factors that underlie differences in attitudes and beliefs about COVID-19 vaccination mandates is essential to advance dialogue and inform educational health campaigns to increase COVID-19 vaccination rates., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

COVID-19 vaccine uptake in the Federation of Bosnia and Herzegovina (FBiH) accelerated in the second half of 2021, with greater vaccine availability. In this study, we estimated the vaccine effectiveness (VE) of complete primary series BBIBP-CorV vaccine against COVID-19 in patients aged 60 years and older, during the Delta-dominant period, using a test-negative case-control design. Surveillance sites were 11 primary health care centers (PHC) collecting patient data from October 1, 2021, to January 4, 2022, retrospectively according to a common protocol. In total, we included 1711 participants in the analysis: 933 cases and 778 controls. Of the 933 cases, 508 (54.4 %) had mild and 425 (45.6 %) had moderate to severe disease presentation. We observed no effectiveness against mild COVID-19. Overall vaccine effectiveness was 65.0 % (95 %CI: 40.1-79.5) against moderate to severe COVID-19. In time since vaccination analysis, VE was 78.7 % (95 % CI: 54.8-89.9) in patients who received their last dose < 90 days before onset; 66.0 % (95 % CI: -0.5-88.5) in those 90-119 days before onset; 42.1 % (95 % CI: -88.6-82.3) in those 120-149 days before onset and 45.0 % (95 % CI: -94.0-84.4) in those ≥ 150 days before onset. In our study, two doses of BBIBP-CorV provided considerable protection against moderate to severe COVID-19 in older adults, highest within 3 months after second dose, during the Delta-dominant period. Point estimates declined thereafter, suggesting a need for additional doses., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Factors related with COVID-19 vaccine uptake in children and adolescents in Norway remain unclear, despite this being useful knowledge for future pandemic preparedness. This study aimed to comprehensively examine individual and familial factors associated with vaccine uptake in children and adolescents in Norway. We utilized nationwide registry-data from various health registries and Statistics Norway, encompassing all children and adolescents living in Norway during the pandemic, until 31-Dec-2022. Vaccine uptake is defined as receiving at least one dose of COVID-19 vaccine. We employed a forward stepwise logistic regression model and a random forest machine-learning algorithm to explore the relationship between vaccine uptake and socio-cultural, demographic, and health-related factors. We included 423,548 5-11-year-olds, 269,830 12-15-year-olds, and 120,854 16-17-year-olds. Vaccine uptake in these three groups was respectively 2.6 %, 73.3 %, and 87.3 %. Factors associated with vaccine uptake varied by age group. In youngest children, immigrant background (Odds-ratio (OR) = 1.58, 95 % confidence interval (CI) (1.14-2.19)), born extremely preterm (OR = 2.38, 95 % CI (1.60-3.54)), having risk of severe COVID-19 (OR = 5.40, 95 % CI (4.69-6.23) and maternal COVID-19 vaccination (OR = 6.34, 95 % CI (5.35-7.53)) were positively associated with vaccine uptake. The latter two factors were also strongly, positively associated with vaccine uptake in 12-15-year-olds, while previous SARS-CoV-2 infection was negatively associated (OR = 0.12, 95 % CI (0.11-0.14). Similar findings were observed in 16-17-year-olds. COVID-19 vaccine uptake differed markedly by age group, and major associated factors included socio-demographics and parental COVID-19 vaccination status, prior SARS-CoV-2 infection, but also being born premature and having moderate or high risk of severe COVID-19., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Previous research suggested that the inactivated influenza vaccine (IIV) may protect against SARS-CoV-2 infection or a severe course of COVID-19. These findings were however based on cohort studies, that are prone to confounding by indication. We examined the association between IIV and SARS-Cov-2 infection in a Dutch population using a test-negative design., Methods: This test-negative case-control study was conducted in adults (≥60) who tested because of COVID-19 like symptoms at community SARS-CoV-2 testing locations in the Netherlands during the period of November 8th 2021-March 11th 2022. Information on receipt of IIV in October-November 2021 was routinely collected at each visit. Logistic regression was used to calculate unadjusted, partially (sex, age, education level) and fully adjusted (COVID-19 vaccination, IIV 2020) odds ratios (ORs) for receipt of IIV in SARS-CoV-2 positive versus negative subjects. Differential effects on SARS-CoV-2 risk by time since IIV were investigated by including an interaction term for calendar time: November 2021-January 2022 vs February-March 2022., Results: In total, 1,832 participants were included in the main analysis, of whom 336 (18.3 %) had a positive SARS-CoV-2 test. No significant association between IIV and SARS-CoV-2 infection was found; fully adjusted OR of 1.07 (95 % CI: 0.78-1.49). The interaction term for time periods was not significant (1.04 [95 % CI: 0.51-2.15], p = 0.91). Results were robust in sensitivity analyses., Conclusions: While earlier observational studies suggested a protective non-specific effect of IIV and SARS-CoV-2 infections, this smaller, but well controlled test-negative design study does not suggest an effect, either positive or negative. Larger test-negative design studies, or alternative designs such as the self-controlled case series design are needed to confirm these findings and provide more definite answers on the topic., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier India Pvt Ltd. Published by Elsevier Ltd. All rights reserved.)

Background: A global shift to bivalent mRNA vaccines is ongoing to counterbalance the diminishing effectiveness of the original monovalent vaccines due to the evolution of SARS-CoV-2 variants, yet substantial variation in the bivalent vaccine effectiveness (VE) exists across studies and a complete picture is lacking., Methods: We searched papers evaluating absolute or relative effectiveness of SARS-CoV-2 BA.1 type or BA.4/5 type bivalent mRNA vaccines on eight publication databases published from September 1st, 2022, to November 8th, 2023. Pooled VE against Omicron-associated infection and severe events (hospitalization and/or death) was estimated in reference to unvaccinated, ≥2 original monovalent doses, and ≥ 3 original monovalent doses., Results: From 630 citations identified, 28 studies were included, involving 55,393,303 individuals. Bivalent boosters demonstrated higher effectiveness against symptomatic or any infection for all ages combined, with an absolute VE of 53.5 % (95 % CI: -22.2-82.3 %) when compared to unvaccinated and relative VE of 30.8 % (95 % CI: 22.5-38.2 %) and 28.4 % (95 % CI: 10.2-42.9 %) when compared to ≥ 2 and ≥ 3 original monovalent doses, respectively. The corresponding VE estimates for adults ≥ 60 years old were 22.5 % (95 % CI: 16.8-39.8 %), 31.4 % (95 % CI: 27.7-35.0 %), and 30.6 % (95 % CI: -13.2-57.5 %). Pooled bivalent VE estimates against severe events were higher, 72.9 % (95 % CI: 60.5-82.4 %), 57.6 % (95 % CI: 42.4-68.8 %), and 62.1 % (95 % CI: 54.6-68.3 %) for all ages, and 72.0 % (95 % CI: 51.4-83.9 %), 63.4 % (95 % CI: 41.0-77.3 %), and 60.7 % (95 % CI: 52.4-67.6 %) for adults ≥ 60 years old, compared to unvaccinated, ≥2 original monovalent doses, and ≥ 3 original monovalent doses, respectively., Conclusions: The bivalent boosters demonstrated superior protection against severe outcomes than the original monovalent boosters across age groups, highlighting the critical need for improving vaccine coverage, especially among the vulnerable older subpopulation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier India Pvt Ltd. All rights reserved.)

Background: Vaccines were developed and deployed to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study aimed to characterize patterns in the protection provided by the BNT162b2 and mRNA-1273 mRNA vaccines against a spectrum of SARS-CoV-2 infection symptoms and severities., Methods: A national, matched, test-negative, case-control study was conducted in Qatar between January 1 and December 18, 2021, utilizing a sample of 238,896 PCR-positive tests and 6,533,739 PCR-negative tests. Vaccine effectiveness was estimated against asymptomatic, symptomatic, severe coronavirus disease 2019 (COVID-19), critical COVID-19, and fatal COVID-19 infections. Data sources included Qatar's national databases for COVID-19 laboratory testing, vaccination, hospitalization, and death., Results: Effectiveness of two-dose BNT162b2 vaccination was 75.6% (95% CI: 73.6-77.5) against asymptomatic infection and 76.5% (95% CI: 75.1-77.9) against symptomatic infection. Effectiveness against each of severe, critical, and fatal COVID-19 infections surpassed 90%. Immediately after the second dose, all categories-namely, asymptomatic, symptomatic, severe, critical, and fatal COVID-19-exhibited similarly high effectiveness. However, from 181 to 270 days post-second dose, effectiveness against asymptomatic and symptomatic infections declined to below 40%, while effectiveness against each of severe, critical, and fatal COVID-19 infections remained consistently high. However, estimates against fatal COVID-19 often had wide 95% confidence intervals. Analogous patterns were observed in three-dose BNT162b2 vaccination and two- and three-dose mRNA-1273 vaccination. Sensitivity analyses confirmed the results., Conclusion: A gradient in vaccine effectiveness exists and is linked to the symptoms and severity of infection, providing higher protection against more symptomatic and severe cases. This gradient intensifies over time as vaccine immunity wanes after the last vaccine dose. These patterns appear consistent irrespective of the vaccine type or whether the vaccination involves the primary series or a booster., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Widely documented psychological antecedents of vaccination are confidence in vaccines, complacency, convenience, calculation, collective responsibility (5C model) with the recent addition of confidence in the wider system and social conformism. While the capacity of these seven antecedents (7C) to explain variance in COVID-19 vaccine intentions has been previously documented, we study whether these factors also are associated with vaccine behaviours, beyond intentions., Methods: From February to June 2022, we recruited a sample of adults in France, including persons with notified recent SARS-CoV-2 infection, along with relatives and randomly selected non-infected persons. Participants completed self-administered questionnaires assessing COVID-19 vaccination history and the 7C antecedents. We defined vaccination behaviours as three outcomes: at-least-one-dose vaccine status by 2022 (N = 49,019), up-to-date vaccination status (N = 46,566), and uptake speed of first dose (N = 25,998). We conducted multivariable logistic regressions and Cox models., Results: Among the 49,019 participants, 95.0% reported receipt of at least one dose and 89.8% were up to date with recommendations. All 7C antecedents were significantly associated with the outcomes, although effects were weaker for up-to-date vaccination status and uptake speed. The strongest effects (most vs. least vaccine-favourable attitude level, at-least-one-dose vaccination status) were observed for collective responsibility (OR: 14.44; 95%CI: 10.72-19.45), calculation (OR: 10.29; 95%CI: 7.53-14.05), and confidence in the wider system (OR: 8.94; 95%CI: 6.51-12.27)., Conclusion: This study demonstrates that the 7C not only explain vaccine intention, but also vaccine behaviours, and underpins the importance of developing vaccine promotion strategies considering the 7C antecedents., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Vaccines are vital for public health, but concerns about adverse effects, particularly myocarditis and pericarditis linked to COVID-19 vaccines-, persist. This study investigates the application of Brighton Collaboration case definition to national vaccine safety data related to post-COVID-19 vaccine myo/pericarditis, utilizing claims under the Korea National Vaccine Injury Compensation Program (NIVCP)., Methods: This study analyzed 190 medical records of individuals who claimed to have developed myo/pericarditis after receiving the COVID-19 vaccine, as reported to the NVICP between specified dates, categorizing cases based on the Brighton criteria for myocarditis or pericarditis., Results: Between 2021-2022, NVICP received 190 cases meeting the Brighton criteria for myocarditis or pericarditis at levels 1, 2, or 3. Most cases fell into Level 2 (70%), followed by Level 1 (29%), and one at Level 3 (1%), with Level 1 cases showing a higher hospitalization rate (87.3%) and a notable proportion requiring admission to the Intensive Care Unit (25.5%). Chest pain and Troponin-I/T elevation were common findings in Level 1 cases, while Level 2 cases exhibited similar patterns but at a slightly lower frequency. Electrocardiogram and echocardiography findings differed between the two levels., Conclusion: The Brighton Collaboration case definition proved valuable for classifying and assessing AEFI data, enhancing our understanding of the potential relationship between myocarditis and the COVID-19 vaccine., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Young June Choe reports financial support was provided by Korea Disease Control and Prevention Agency. Young June Choe reports a relationship with Korea Disease Control and Prevention Agency that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Examining the spectrum of vaccine attitudes within the general public, spanning from hesitancy to confidence, is pivotal in addressing the challenges posed by the COVID-19 pandemic. Despite widespread campaigns advocating for vaccine uptake, a proportion of the population harbour reservations about the safety and efficacy of vaccines. This study seeks to explore the determinants of vaccine attitudes in Canada, leveraging key concepts from the well-established Self-Determination Theory (SDT), including basic psychological needs and the quality of an individual's motivation. During a crucial juncture in the COVID-19 pandemic (December 2021), 292 participants were recruited and completed an online survey assessing levels of satisfaction/frustration of basic psychological needs (sense of autonomy, relatedness, and competence), vaccine attitudes (confidence and hesitancy), and motivation towards vaccination (controlled and autonomous). Two mediation models were employed to examine whether autonomous-controlled motivation mediated the relationship between need satisfaction-frustration and vaccine attitudes. Model 1 revealed a full mediating effect, indicating that need satisfaction influenced vaccine confidence only through autonomous motivation (ab 1  = 0.09, SE = 0.04, z = 2.19, 95 % CI [0.01, 0.18]). Meanwhile, Model 2 demonstrated that need frustration was associated with vaccine hesitancy partially through controlled motivation (ab 2  = 0.05, SE = 0.02, z = 2.54, 95 % CI [0.02, 0.10]). These findings underscore the applicability of SDT in investigating the motivational mechanisms that shape vaccine attitudes. Recognizing psychosocial factors, including the balance of basic needs and quality of motivations, may be integral to informing effective public health strategies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: COVID-19 vaccination is critical for reducing serious illness and hospitalizations, yet many remain hesitant. We conducted a survey of frontline physicians to identify patient concerns and physician strategies to address COVID-19 vaccine-hesitancy., Methods: A national random sample of physicians in frontline specialties selected from a comprehensive list of practicing physicians in the U.S. were emailed a survey in August 2021. Multiple choice and open-ended questions inquired about patient concerns related to the COVID-19 vaccines and strategies used by physicians to counter vaccine misinformation and encourage vaccine-hesitant patients. Weighting was applied to achieve representativeness and reduce non-response bias. Network analysis examined co-occurring patient concerns. Open-ended responses on communication strategies were coded via thematic analysis. Multi-variable logistic regression examined associations between physician and pandemic characteristics with patient concerns and use of communication strategies., Results: 531 physicians responded: primary care (241); emergency medicine (142); critical care (84); hospitalists (34); and infectious disease (30). Weighted response balance statistics showed excellent balance between respondents and nonrespondents. On average, physicians reported four patient vaccine concerns. Safety, side effects, vaccine misinformation, and mistrust in government were most common, and often co-occurring. 297 physicians described communication strategies: 180 (61 %) provided vaccine education and 94 (32 %) created a safe space for vaccine discussion. Narrative responses from physicians provided compelling examples of both successes and communication challenges arising from misinformation. Compared with emergency medicine, critical care (OR 2.45, 95 % CI 1.14, 5.24), infectious disease (OR 2.45, 95 % CI 1.00, 6.02), and primary care physicians (OR 1.66, 95 % CI 1.02, 2.70) were more likely to provide communication strategies., Conclusions: Many physicians engage with vaccine hesitant patients using a variety of strategies. Dissemination of effective system and physician-level communication interventions could enhance physician success., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)