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Background: A vaccination programme against severe acute respiratory syndrome coronavirus 2 was initiated in Portugal in December 2020. In this study, we report the findings of a prospective cohort study implemented with the objective of monitoring antibody production in response to COVID-19 vaccination. Methods: The humoral immune response to vaccination was followed up using blood samples collected from 191 healthcare workers. Participants were split into three groups: the Oxford-AstraZeneca (Vaxzevria) vaccine group (n = 68), the Pfizer-BioNTech COVID-19 (Comirnaty) vaccine group (n = 51), and the Post-COVID group (n = 72). The kinetics of anti-spike antibody production were evaluated until 56 days on average after the third dose (booster). Results: We observed that antibody titres peaked approximately one month after full vaccination and declined steadily thereafter. We also found that mRNA vaccination induces higher titres of antibodies than viral vector vaccination, and both generate greater antibody responses than mild or moderate COVID-19. Additionally, whilst the booster for the Oxford-AstraZeneca and Pfizer-BioNTech groups led to antibody levels higher than those at any previous sample collection point, the booster for the Post-COVID group (persons with a history of COVID-19 prior to vaccination) led to antibody levels lower than those attained one month after the second dose. Interpretation: Our results indicate that there are different kinetics of antibody production between individuals who received the Pfizer-BioNtech mRNA vaccine and those who received the Oxford-AstraZeneca vector vaccine, or individuals who had COVID-19 before being vaccinated. Additionally, we observed that exposure to either natural infection or vaccination modulates the response to subsequent vaccination. This is particularly evident after administration of the third dose to the Post-COVID group, where our findings point to a hindrance in vaccine boosting, probably due to unwanted feedback by high titres of pre-existing antibodies. [ABSTRACT FROM AUTHOR]

Despite the availability of a highly efficacious vaccine, a global resurgence of measles infections has occurred, largely due to decreased vaccination coverage and waning immunity following the two‐dose vaccination schedule. This study aims to assess the cellular immune response in individuals who did not respond to the two‐dose MMR vaccine and evaluate the efficacy and durability of immune responses after booster doses. An observational study was conducted involving 24 individuals who were seronegative for measles years after completing the two‐dose MMR vaccine schedule. Of these, 11 seroconverted after a single booster dose, while 13 required an additional booster. Antibody levels were monitored 1 and 3 years post‐booster. Cellular immune responses were evaluated in 10 nonresponders by in vitro stimulation of PBMCs with UV‐inactivated measles virus. In nonresponders, measles virus stimulation did not induce significant alterations in T, B, or NK cell populations, indicating a lack of measles‐specific immune memory. However, stimulation with rubella induced a significant immune response. Booster doses in subjects with waning antibodies resulted in low IgG titers, which significantly declined over 3 years. Neutralizing antibody titers were also low for both double and single booster recipients. This study highlights the limited long‐term efficacy of booster doses in individuals with waning immunity or nonresponsiveness to the measles vaccine. Current vaccination strategies relying on booster doses may not be sufficient for sustained protection in these individuals. Improving vaccine formulations to elicit stronger and longer‐lasting immunity is essential for effective measles control and elimination. [ABSTRACT FROM AUTHOR]

Objective: Pakistan has been seriously affected by the COVID-19 pandemic, with numerous waves of infection. Using different vaccine and booster doses was a key component to control and combat this pandemic. This study aims to monitor the heterologous and homologous booster vaccination doses that generate immune responses in healthy adults after 9 months of vaccination. Methods: In this cross-sectional, observational study a total of 173 samples were collected. Participants from both genders (Male and Female) between the ages of 18 to 25 years were enrolled for the study. Participants who had booster shots of homologous Sinopharm BBIBP CorV and heterologous Pfizer-BioNTech vaccines were included only, with the use of a Roche Cobas-e601 analyzer, the antibody titers in the blood serum were quantified by the ECLIA method. IBM SPSS 22 was utilized for descriptive statistical analysis and P< 0.05 was considered significant. Results: In this study the IgG antibody levels were measured against the full length of receptor binding domain (RBD) of the spike (S) protein. The mean antibody titer in the Pfizer group was 9764 ± 10976 U/mL and 5762 ± 4302 U/mL in the Sinopharm group. The Mean IgG antibody levels of the Pfizer-vaccinated group were significantly higher than the Sinopharm-vaccinated group (P=0.000, each). Comparing the Sinopharm BBIBP CorV booster dosage to the Pfizer booster, Pfizer BNT162b2demonstrated a stronger immune response. However, there were no immunological gender-specific significant differences. The administration of a third dosage of Pfizer BNT162b2 after two doses of BBIBP CorV Conclusion: The administration of a third dosage of Pfizer BNT162b2 after two doses of BBIBP-CorV is recommended to boost the humoral immune response in the general population while there was no gender-specific difference observed. More effectiveness can be attained by administering additional doses due to the antibody decay. [ABSTRACT FROM AUTHOR]

Background: As the COVID-19 virus spreads, it has new opportunities to change, and new variants of the virus are expected to occur. Health care workers (HCWs) are potential victims of the disease and spread it. They are more vulnerable to infection due to their occupational and nonoccupational exposure. The aim of this study was to identify the frequency and determinants of the acceptance of health care providers to receive the booster dose of COVID-19 vaccine. Methods: An online questionnaire was used to collect data by the Egyptian HCWs. The questionnaire had four sections: the first section included the participants' sociodemographic data, the second section included data on the participants' previous COVID-19 infection status, the third section was on COVID-19 vaccine-related information, and the fourth section evaluated the intention to take the booster dose, causes of acceptance or refusal, and any suggestions to combat COVID-19. Results: A total of 413 HCWs completed the questionnaire. Females represented 79.9%, and 37.3% had direct contact with COVID-19 patients, and 61.7% had previous infection. The vast majority (94.2%) received COVID-19 vaccine, 52.1% agreed to receive the booster dose, while 47.9% refused. The most common reason to receive booster dose was for increasing protection against new variants (48.4%) and lowering rate of severe illness and hospitalization (41.4%). Male gender and previous COVID-19 vaccination were the main determining factors of acceptance to receive booster doses. Conclusion: Acceptance of COVID-19 booster vaccination was relatively inadequate among the HCWs. Male gender and previous COVID-19 vaccination were determinants of acceptance. [ABSTRACT FROM AUTHOR]

Background Data on protection afforded by updated coronavirus disease 2019 (COVID-19) vaccines (bivalent/XBB 1.5 monovalent) against the emergent JN.1 variant remain limited. Methods We conducted a retrospective population-based cohort study among all boosted Singaporeans aged ≥18 years during a COVID-19 wave predominantly driven by JN.1, from 26 November 2023 to 13 January 2024. Multivariable Cox regression was used to assess risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19–associated emergency department (ED) visits/hospitalizations, stratified by vaccination status/prior infection; with individuals last boosted ≥1 year used as the reference category. Vaccination and infection status were classified using national registries. Results A total of 3 086 562 boosted adult Singaporeans were included in the study population, accounting for 146 863 476 person-days of observation. During the JN.1 outbreak, 28 160 SARS-CoV-2 infections were recorded, with 2926 hospitalizations and 3747 ED visits. Compared with individuals last boosted ≥1 year earlier with ancestral monovalent vaccines, receipt of an updated XBB.1.5 booster 8–120 days earlier was associated with lower risk of JN.1 infection (adjusted hazard ratio [aHR], 0.59 [95% confidence interval (CI),.52–.66]), COVID-19–associated ED visits (0.50 [.34–.73]), and hospitalizations (0.58 [.37–.91]), while receipt of a bivalent booster 121–365 days earlier was associated with lower risk of JN.1 infection (0.92 [.88–.95]) and ED visits (0.80 [.70–.90]). Lower risk of COVID-19 hospitalization during the JN.1 outbreak (aHR, 0.57 [95% CI,.33–.97]) was still observed following receipt of an updated XBB.1.5 booster 8–120 days earlier, even when analysis was restricted to previously infected individuals. Conclusions Recent receipt of updated boosters conferred protection against SARS-CoV-2 infection and ED visits/hospitalizations during a JN.1 variant wave, in both previously infected and uninfected individuals. Annual booster doses confer protection during COVID-19 endemicity. [ABSTRACT FROM AUTHOR]

Energy supply is one of the most significant issues in modern society. So, energy saving becomes important in systems used frequently in daily life. Due to these energy saving concerns, there are numerous studies in literature to make supermarket refrigeration systems consume less energy. Among these studies, CO2 booster refrigeration system with flooded evaporators and parallel compressor (BFP) seems as an energysaving and nature-friendly choice. In this study, BFP was selected as the system of concern and the Bees Algorithm optimization was applied to get minimum power consumption (maximum COP). Gas cooler pressure (Pgc), intermediate pressure (Pint), and medium temperature (MT) level evaporator outlet quality(x14) were chosen as optimization parameters. According to the optimization results, the Bees Algorithm converged well, and these three parameters were found worthy to optimize as they brought significant energy saving in total (up to 8.7% in comparison with constant intermediate pressure and MT evaporator outlet quality). As a result of this analysis, the optimal Pgc values were found to be between 7600 kPa and 12000 kPa at ambient temperatures ranging from 28 to 46°C. The optimal Pint values were found to be around 3500 kPa below ambient temperature of 14 °C and around 4500 kPa above this temperature. The optimal values for x14 ranged between 0.62 and 0.69. Additionally, annual energy consumption (AEC) and total equivalent emission (TEE) for 15 years were calculated for four different climate types. The highest AEC and TEE were obtained at tropical climate with 728.56 MWh and over 10000 tons, respectively. The lowest AEC and TEE were found at continental conditions as 380.01 MWh and almost 6000 tons of emission. [ABSTRACT FROM AUTHOR]

Although a fourth dose of SARS-CoV-2 vaccine was shown to be effective, the immunogenicity of a fifth dose in immunocompetent individuals had not been well described. This was a prospective observational cohort study of previously vaccinated healthcare workers at a single tertiary hospital in Israel. Individuals were administered up to three booster doses of the BNT162b2 mRNA vaccine (i.e., up to five overall doses), during the period between July 2021 and January 2023. Immunogenicity was assessed using the SARS-CoV-2 IgG (sCOVG) semi-quantitative assay, performed at several time points. The cohort consisted of 162 individuals (median age 69 years, 62% female). Of these, 104 (64%) received four doses and 58 (36%) received five doses. Anti-SARS-CoV-2 antibody levels increased in all cases, regardless of the baseline levels. The fold-change increase in the mean sCOVG index was 29.2 (SD 2.6) after the third vaccine, 3.8 (SD 2.4) after the fourth vaccine, and 3.6 (SD 3.0) after the fifth vaccine. A waning effect over time was seen in 78% and 43% of participants for the third and fourth doses, respectively. Adverse events following the fifth dose were limited and mild. Similar to previous booster vaccines, a fifth dose of BNT162b2 is immunogenic and safe in healthy individuals, although the clinical implications remain unclear. [ABSTRACT FROM AUTHOR]

Protective antibodies in the upper respiratory tract prevent the spread of COVID-19 in the community. Intranasal vaccines could raise the specific secretory IgA and IgG levels. This is a single-center, randomized, double-blind, placebo-controlled clinical trial to evaluate the safety and immunogenicity of Razi Cov Pars (RCP) intranasal recombinant protein subunit COVID-19 vaccine as a booster in adults. We compared specific IgG and IgA levels in the intranasal RCP group (n = 97) versus placebo (n = 96) in serum, saliva, and nasal mucosal secretions on days 0 and 14 and reported their Geometric Mean Ratios (GMR) and 95% confidence intervals (CI). We showed significant increases in IgA and IgG anti-RBD in the nasal mucosa in the RCP group, but their increase was not detectable in the serum and saliva. Anti-spike IgA in the nasal mucosa also increased in the RCP group compared to the placebo. This increase against the COVID-19 variant Omicron was also similar to that of the Wuhan. We detected no serious adverse reactions or anaphylaxis and all adverse events resolved completely during the follow-up period and were similar in both groups. Intranasal RCP is safe, stimulates the respiratory mucosal immunity, and could be a booster on various COVID-19 vaccines and be effective against new virus variants. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to estimate the effectiveness of original and bivalent COVID-19 vaccines in reducing COVID-19-associated hospitalizations among the adult population of Turin, Italy. Methods: We conducted a retrospective, test-negative, case–control study of 5768 adults aged ≥50 years who had symptoms that were consistent with COVID-19-like illness and were admitted to the hospitals of the Turin Health Unit network from 1 January 2021 to 31 January 2023. We evaluated the effectiveness of the vaccines that at the time of the study were authorized in the European Union (original/bivalent BNT162b2; original mRNA-1273; ChAdOx1-S; Ad26.COV2.S) by comparing the odds of a positive test for SARS-CoV-2 in vaccinated patients with the odds of a positive test in unvaccinated patients. The association between vaccination status, hospitalization, ICU admission and positive SARS-CoV-2 test was estimated by building multivariate adjusted logistic regression models. Results: During the predominance of the pre-Omicron variants, the vaccine effectiveness of two and three doses received in the last 120 days against COVID-19-associated hospitalizations was 93.6% (95% CI: 90.1 to 95.9) and 97.1% (95% CI: 90.8 to 99.1), respectively. During the predominance of the Omicron variant, the vaccine effectiveness of two and three doses was 26.6% (95% CI: −0.6 to 46.5) and 75.2% (95% CI: 68.1 to 80.7), respectively, and it rose to 88% (95% CI: 78.2 to 93.3) for four or five doses of the bivalent vaccine. Conclusions: Our study confirms that the COVID-19 vaccines protect adult patients from hospitalizations, including the subgroup ≥80 years, also during the period of the Omicron variant's predominance. [ABSTRACT FROM AUTHOR]

Introduction Vaccination against SARS-CoV-2 is an integral pillar of the public health approach to COVID-19. With the emergence of variants of concern that increase transmissibility and escape from vaccine- or infection-induced protection, vaccines have been developed to more closely match the newly circulating SARS-CoV-2 strains to improve protection. The safety and immunogenicity of multiple authorized messenger RNA (mRNA)-based COVID-19 vaccines targeting the omicron sublineage (BA.1, BA.4/BA.5, and XBB.1.5) have been demonstrated in several clinical trials among adults and children.Areas covered This review will comprehensively detail the available evidence (published through July 2024) from ongoing clinical trials on omicron variant-containing mRNA-1273 vaccines administered as additional doses in previously vaccinated target demographics.Expert opinion Across three clinical trials, omicron variant-containing mRNA-1273 vaccines induced immune responses to vaccine-matched omicron strains as well as ancestral SARS-CoV-2, with a safety and reactogenicity profile comparable to the original mRNA-1273 vaccine. Combined with pivotal data demonstrating the safety, efficacy, and effectiveness of the original mRNA-1273 vaccine, these findings support the use of variant-containing mRNA-1273 vaccines and provide confidence that expeditious development of updated vaccines using this established mRNA platform can maintain protection against COVID-19.

Background The aim of this study was to evaluate the public health and economic impact of the COVID-19 booster vaccination with BNT162b2 in Japan during an Omicron-dominant period from early 2022.Research design and methods A combined cohort Markov decision tree model estimated the cost-effectiveness of annual or biannual booster vaccination strategies compared to no booster vaccination for those aged 65 years and above, and those aged 60–64 years at high risk as the base case. The societal perspective was primarily considered. We also examined other target populations with different age and risk groups. Sensitivity and scenario analyses with alternative inputs were performed.Results Annual and biannual vaccination strategies were dominant from the societal perspective in the base case. Incremental Cost Effectiveness Ratios (ICERs) from the payer perspective were JPY 1,752,499/Quality Adjusted Life Year (QALY) for annual vaccination and JPY 2,831,878/QALY for biannual vaccination, both less than the threshold value in Japan (JPY 5 million/QALY). The results were consistent even when examining other target age and risk groups. All sensitivity and scenario analyses indicated that ICERs were below JPY 5 million/QALY.Conclusions Booster vaccination with the COVID-19 vaccine BNT162b2 is a dominant strategy and beneficial to public health in Japan.

Abstract Background As the COVID-19 virus spreads, it has new opportunities to change, and new variants of the virus are expected to occur. Health care workers (HCWs) are potential victims of the disease and spread it. They are more vulnerable to infection due to their occupational and nonoccupational exposure. The aim of this study was to identify the frequency and determinants of the acceptance of health care providers to receive the booster dose of COVID-19 vaccine. Methods An online questionnaire was used to collect data by the Egyptian HCWs. The questionnaire had four sections: the first section included the participants’ sociodemographic data, the second section included data on the participants’ previous COVID-19 infection status, the third section was on COVID-19 vaccine-related information, and the fourth section evaluated the intention to take the booster dose, causes of acceptance or refusal, and any suggestions to combat COVID-19. Results A total of 413 HCWs completed the questionnaire. Females represented 79.9%, and 37.3% had direct contact with COVID-19 patients, and 61.7% had previous infection. The vast majority (94.2%) received COVID-19 vaccine, 52.1% agreed to receive the booster dose, while 47.9% refused. The most common reason to receive booster dose was for increasing protection against new variants (48.4%) and lowering rate of severe illness and hospitalization (41.4%). Male gender and previous COVID-19 vaccination were the main determining factors of acceptance to receive booster doses. Conclusion Acceptance of COVID-19 booster vaccination was relatively inadequate among the HCWs. Male gender and previous COVID-19 vaccination were determinants of acceptance.

Abstract Background In the pursuit of global health security, continuous monitoring of vaccine effectiveness across various viral strains emerges as a crucial imperative. The emergence of SARS-CoV-2 major variants of concern (VOCs), including Alpha, Beta, Delta, and Omicron, has added complexity to the COVID-19 vaccination landscape. Objectives To assess illness severity, evaluate vaccine efficacy across varying doses and types, and determine effectiveness against major VOCs within the population. Methods This retrospective cohort study, conducted in Abu Dhabi, United Arab Emirates, focuses on a cohort of 44,073 SARS-CoV-2 positive cases from February 2021 to May 2022, dominated by the Delta and Omicron variants. The study employed a nested case-control design, analyzing hospital admissions for confirmed SARS-CoV-2 infection. Results Vaccine effectiveness was higher among heterologus-boosted individuals at 87% (95% CI:79%-93%) compared to homologus-boosted individuals at 59% (95% CI: 48%-68%) and fully vaccinated, non-boosted adults at 53% (95% CI: 46%-59%). These findings highlight the importance of heterologous boosting, particularly against rapidly evolving viral variants, offering valuable insights for refining pandemic response strategies. Conclusion The study underscores the critical need for ongoing assessment and adaptation of vaccination strategies to the evolving viral landscape.

ObjectiveTo summarize the clinical effect of using boosters for orbital autologous fat injection transplantation.MethodsA retrospective analysis was conducted on the clinical data of patients who underwent orbital fine autologous fat injection and transplantation at the Burn and Plastic Surgery Department of the 940th Hospital of the PLA Joint Logistics Support Force from January 2019 to December 2023. The patients were treated with orbital fine autologous fat injection and transplantation using a self-developed autologous fat transplantation booster with constant pressure and micro controllability connected to a 1 mL injector, and the therapeutic effect was analyzed.ResultsA total of 186 patients who met the inclusion and exclusion criteria were included in this study, including 165 females and 21 males, with the average age of (39.0±7.1) years old (range: 23-71 years old). Of the 186 patients, 58 cases were of upper eyelid depression, 45 cases were of inner canthal depression, 34 cases were of ocular platform flattening, 6 cases were of meibomian depression, and 43 cases were of lacrimal groove depression. The transplantation volume of granular fat was 0.1-10 mL, with an average of 3.5 mL; the injection volume of nanofat was 0.5-2.0 mL, with an average of 0.5 mL. Follow up for 7 days to 4 years showed that 163 cases (87.6%) were satisfied with the results, 15 cases (8.1%) had average results, and 8 cases (4.3%) were dissatisfied. No surgical complications occurred.ConclusionThe use of a constant pressure and micro controllable electric booster to assist autologous fat injection transplantation could achieve precision in orbital autologous fat transplantation, with high patient satisfaction, meaning that it is worthy of clinical promotion and application.

Abstract Introduction Japan will be transitioning from the free-of-charge COVID-19 vaccination program to annual periodic vaccination under a national immunization program for old adults and high-risk patients from 2024 fall/winter season. The policy transition including out-of-pocket payment requirement may discourage vaccination, leading to a lower vaccination rate. This study aimed to estimate the impact of varying vaccination rates with BNT162b2 COVID-19 mRNA vaccine on economics and public health in an illustrative prefecture which administers and promotes the periodic vaccination program, using budget impact analysis. Methods A combined cohort Markov decision tree model estimated the public health outcomes of COVID-19-related symptomatic cases, hospitalizations and deaths; and the economic outcomes including vaccine-related cost, non-vaccine-related medical cost, and productivity loss from the societal perspective. The base case examined the impact on the outcomes when vaccination coverage changed from the reference value of 50% to upper and lower values, respectively. Scenario analyses were performed based on multiple scenarios. Results Increase in the vaccination rate demonstrated improvement in all public health outcomes. At 50% vaccination, the vaccine-related cost for 3 years in a prefecture was estimated at JPY 7.58 billion (USD 57.67 million), the non-vaccine-related medical cost at JPY 79.22 billion (USD 602.48 million), the productivity loss at JPY 253.11 billion (USD 1.92 billion), and the total cost at JPY 339.92 billion (USD 2.59 billion). When the vaccination rate increased to 90%, the total cost decreased by JPY 4.88 billion (USD 37.11 million) (1.4%). When the vaccination rate decreased to 10%, the total cost increased by JPY 5.73 billion (USD 43.58 million) (1.7%). Results were consistent across almost all scenario analyses. Conclusions Maintaining a high vaccination rate with BNT162b2 is important from both public health and economic perspectives in Japan. The findings highlight to local governments the importance of continued effort to promote vaccination.

Abstract Background Previous research has shown that repeated COVID-19 mRNA vaccination leads to a marked increase of SARS-CoV-2 spike-specific serum antibodies of the IgG4 subclass, indicating far-reaching immunoglobulin class switching after booster immunization. Considering that repeated vaccination has been recommended especially for older adults, the aim of this study was to investigate IgG subclass responses in the ageing population and assess their relation with Fc-mediated antibody effector functionality. Results Spike S1-specific IgG subclass concentrations (expressed in arbitrary units per mL), antibody-dependent NK cell activation, complement deposition and monocyte phagocytosis were quantified in serum from older adults (n = 38–50, 65–83 years) at one month post-second, -third and -fifth vaccination. Subclass distribution in serum was compared to that in younger adults (n = 64, 18–47 years) at one month post-second and -third vaccination. Compared to younger individuals, older adults showed increased levels of IgG2 and IgG4 at one month post-third vaccination (possibly related to factors other than age) and a further increase following a fifth dose. The capacity of specific serum antibodies to mediate NK cell activation and complement deposition relative to S1-specific total IgG concentrations decreased upon repeated vaccination. This decrease associated with an increased IgG4/IgG1 ratio. Conclusions In conclusion, these findings show that, like younger individuals, older adults produce antibodies with reduced functional capacity upon repeated COVID-19 mRNA vaccination. Additional research is needed to better understand the mechanisms underlying these responses and their potential implications for vaccine effectiveness. Such knowledge is vital for the future design of optimal vaccination strategies in the ageing population.

Abstract Background Vaccination of healthcare workers (HCWs) is pivotal in decreasing the incidence of contagious infections in hospital settings. In this study, we assessed the knowledge, attitude, and practice regarding HCWs’ recommended vaccines among medical students and interns in Egypt. Methods A multicenter, cross-sectional study was conducted using a structured, pilot-tested, and self-administered questionnaire among Egyptian medical students and interns. We invited 1332 participants to our survey using a systematic random sampling that included participants across nine medical schools in Egypt during the 2021–2022 academic year. Results Out of 1332 participants, 1141 completed our questionnaire with a response rate of 85.7%. Overall, 43% of the participants had intermediate knowledge (knew 2–3 HCWs’ recommended vaccines). Furthermore, 36.7% had received a booster dose of at least one of the HCWs’ recommended vaccines over the last 10 years, with only 6.1% having received all recommended vaccines. Hepatitis B vaccine was the most widely known (71%) and received (66.7%). Interns were more likely to know, receive, and recommend HCWs’ recommended vaccines. The majority (> 90%) agreed that vaccination is beneficial and safe, with a median score of eight (interquartile range [IQR: Q25-Q75]: 7–9) out of ten for vaccine efficacy and eight (IQR: 7–8) for safety. However, the median score for hesitancy was five (IQR: 2–7). The most common influential and limiting factors for vaccination were scientific facts (60.1%) and fear of vaccine side effects (44.9%). Conclusion Although medical students in Egypt have good knowledge of and attitudes towards vaccination, there is a gap in their practices. Interventions are needed to improve vaccination uptake among medical students in Egypt.

Introduction: Japan will be transitioning from the free-of-charge COVID-19 vaccination program to annual periodic vaccination under a national immunization program for old adults and high-risk patients from 2024 fall/winter season. The policy transition including out-of-pocket payment requirement may discourage vaccination, leading to a lower vaccination rate. This study aimed to estimate the impact of varying vaccination rates with BNT162b2 COVID-19 mRNA vaccine on economics and public health in an illustrative prefecture which administers and promotes the periodic vaccination program, using budget impact analysis. Methods: A combined cohort Markov decision tree model estimated the public health outcomes of COVID-19-related symptomatic cases, hospitalizations and deaths; and the economic outcomes including vaccine-related cost, non-vaccine-related medical cost, and productivity loss from the societal perspective. The base case examined the impact on the outcomes when vaccination coverage changed from the reference value of 50% to upper and lower values, respectively. Scenario analyses were performed based on multiple scenarios. Results: Increase in the vaccination rate demonstrated improvement in all public health outcomes. At 50% vaccination, the vaccine-related cost for 3 years in a prefecture was estimated at JPY 7.58 billion (USD 57.67 million), the non-vaccine-related medical cost at JPY 79.22 billion (USD 602.48 million), the productivity loss at JPY 253.11 billion (USD 1.92 billion), and the total cost at JPY 339.92 billion (USD 2.59 billion). When the vaccination rate increased to 90%, the total cost decreased by JPY 4.88 billion (USD 37.11 million) (1.4%). When the vaccination rate decreased to 10%, the total cost increased by JPY 5.73 billion (USD 43.58 million) (1.7%). Results were consistent across almost all scenario analyses. Conclusions: Maintaining a high vaccination rate with BNT162b2 is important from both public health and economic perspectives in Japan. The findings highlight to local governments the importance of continued effort to promote vaccination. [ABSTRACT FROM AUTHOR]

In order to analyze the effect of temperature changes on the shock initiation performance of HMX–based booster explosive, which consists of 95% HMX and 5% FPM2602 by weight, a temperature calibration test of acceptor was designed. The temperature changes in the booster at low and elevated temperatures under the constraint of steel sleeve were obtained. Based on the temperature calibration results, polymethyl methacrylate (PMMA) was selected as gap material to conduct a small scale gap test (SSGT) of HMX–based booster under different temperature conditions. The corresponding critical gap thickness was tested. Based on SSGT results at different temperatures, the shock initiation processes were simulated by adjusting parameters of ignition and growth reactive rate model. The critical gap thickness and critical initiation pressure of HMX–based booster at different temperatures were numerically predicted. By combining SSGT experimental data and simulation results, the attenuation law and fitting prediction formula of the critical initiation pressure of HMX–based booster were proposed. The mechanism of temperature effect on the shock sensitivity of HMX–based booster explosive was analyzed. The research results indicate that the critical gap thickness of HMX–based booster gradually increases with the rise in temperature, and the critical initiation pressure gradually decreases during the shock initiation process under the heating temperature conditions. In addition, the simulation results show that the heated HMX–based booster under steel constraints becomes more sensitive at high temperatures (>120 °C), while the cooled booster is more insensitive, but its critical initial pressure does not change significantly between 88 °C and 120 °C. The experimental and numerical prediction results are important for the shock initiation safety and design of an insensitive booster explosive. [ABSTRACT FROM AUTHOR]

Background: Understanding the facilitators, barriers and hesitancy to accepting COVID-19 booster doses is important for encouraging recommended vaccination. This evidence brief summarizes literature on the intention to accept or reject COVID-19 vaccine booster doses and the factors associated with intention/uptake among individuals in Canada. Methods: A database of COVID-19 literature established at the Public Health Agency of Canada was searched for articles referencing vaccination and knowledge, attitudes and behaviours towards COVID-19 boosters. A grey literature search of Canadian governmental and academic institutions was also conducted. Primary research conducted in Canada (n=21) and relevant systematic reviews of the global literature (n=8) were included in this evidence brief. Results: Intentions to get a booster dose in the general population have decreased between 2021--2023, with intentions varying across subpopulations. In Canada and within the global systematic reviews, facilitators, barriers and hesitancy were similar. Older age was the most common factor positively associated with intention/uptake of a booster, and the most common motivators were government/healthcare provider recommendations and helping to protect others. The main reasons for hesitancy were concerns about vaccine side effects and a lack of belief in the vaccine's efficacy. Conclusion: Intentions to get a booster dose have decreased in Canada. Understanding the reasons for vaccine hesitancy and motivators for obtaining a booster can help guide future public health COVID-19 booster vaccination programs. [ABSTRACT FROM AUTHOR]

Introduction: As the COVID-19 pandemic becomes an endemic state, still many questions remain regarding the risks and impact of SARS-CoV-2 infection and vaccination in patients with immune-mediated inflammatory diseases (IMIDs) who were excluded from the phase 3 COVID-19 vaccination trials. Methods: The BELCOMID study collected patient data and serological samples from a large, multicentric IMID patient cohort that was prospectively followed during sequential stages of the pandemic. Patients were stratified according to vaccination status into five groups across three sampling periods. Interactions between SARS-CoV-2 infection, COVID-19 vaccination status, IMID-treatment modalities and IMID course were explored. Results: In total, 2165 patients with IBD, a dermatological or rheumatological IMID participated. SARS-CoV-2 infection rates increased over the course of the pandemic and were highest in IMID patients that had refused every vaccine. After baseline COVID-19 vaccination, serologic spike (S)-antibody responses were attenuated by particular types of immune-modulating treatment: anti-TNF, rituximab, JAKi, systemic steroids, combined biologic/immunomodulator treatment. Nonetheless, S-antibody concentration increased progressively in patients who received a booster vaccination, reaching 100% seroconversion rate in patients who had received two booster vaccines. Previous SARS-CoV-2 infection was found as a predictor of higher S-antibody response. Patients who had refused every vaccine showed the lowest rates of S-seroconversion (53.8%). Multiple logistic regression did not identify previous SARS-CoV-2 infection as a risk factor for IMID flare-up. Furthermore, no increased risk of IMID flare-up was found with booster vaccination. Conclusions: Altogether, the BELCOMID study provides evidence for the efficacy and safety of COVID-19 vaccination and confirms the importance of repeated booster vaccination in IMID patients. [ABSTRACT FROM AUTHOR]

Simple Summary: Rabies is causing a serious threat to humans and animals almost worldwide. Immunization against the disease is important in four aspects: public health protection, animal health, economic impact, and regulatory compliance. Rabies affects a wide range of mammals, including domestic pets, livestock, and wild animals. Infected animals, usually bitten by an infected wild animal, suffer from severe neurological symptoms and eventually die. In Israel, mandatory vaccination of dogs as well as wildlife surveillance exists. When it comes to farm animals, the vaccination policy depends on a risk analysis. However, little is known regarding the optimal immunization protocol needed to protect small ruminants. To find an optimal vaccination strategy, we tested the effect of one and two doses of vaccine on sheep and goats. Initially, animals were vaccinated with one dose, and half of them received a second dose (booster) a month later. The level of antibodies was tested a month and a year later. The study demonstrated a different immune response between the different species, as one-dose vaccinated sheep showed a low maintenance of protection a year later, compared with the booster-receiving group. On the other hand, 80% of the goats which received a single dose had a sufficient antibody level a year later. Infrequent rabies cases occur in Israel, endangering humans and animals. While dogs receive mandatory vaccinations, farm animals are vaccinated voluntarily. However, optimal vaccination protocol for small ruminants is lacking. The aim of this study was to test the immunological responses to the rabies vaccine, with or without a booster, in sheep and goats; 70 ewes and 49 does participated in the trial. Following the first vaccine, 88% of the ewes and 100% of the does had a sufficient level of rabies antibodies (>0.5 IU/mL) 30 days post-vaccination. A year later, 82% of the ewes that had received a booster dose remained protected, whereas 46% of the non-boosted ewes had a sufficient antibody level. For does, 83% of those receiving a booster maintained sufficient antibody levels 1 year later; 80% of the non-boosted does remained protected, demonstrating no significant contribution of the booster dose in this group of goats. However, while the initial immunological response of the does was higher, the change in response between 1 month and 12 months post-vaccination differed significantly between species, with a greater titer reduction in the does. Differential immunological responses between individuals and between species warrant longer-term studies to recommend a proper vaccine protocol for each species. [ABSTRACT FROM AUTHOR]

Background: Previous research has shown that repeated COVID-19 mRNA vaccination leads to a marked increase of SARS-CoV-2 spike-specific serum antibodies of the IgG4 subclass, indicating far-reaching immunoglobulin class switching after booster immunization. Considering that repeated vaccination has been recommended especially for older adults, the aim of this study was to investigate IgG subclass responses in the ageing population and assess their relation with Fc-mediated antibody effector functionality. Results: Spike S1-specific IgG subclass concentrations (expressed in arbitrary units per mL), antibody-dependent NK cell activation, complement deposition and monocyte phagocytosis were quantified in serum from older adults (n = 38–50, 65–83 years) at one month post-second, -third and -fifth vaccination. Subclass distribution in serum was compared to that in younger adults (n = 64, 18–47 years) at one month post-second and -third vaccination. Compared to younger individuals, older adults showed increased levels of IgG2 and IgG4 at one month post-third vaccination (possibly related to factors other than age) and a further increase following a fifth dose. The capacity of specific serum antibodies to mediate NK cell activation and complement deposition relative to S1-specific total IgG concentrations decreased upon repeated vaccination. This decrease associated with an increased IgG4/IgG1 ratio. Conclusions: In conclusion, these findings show that, like younger individuals, older adults produce antibodies with reduced functional capacity upon repeated COVID-19 mRNA vaccination. Additional research is needed to better understand the mechanisms underlying these responses and their potential implications for vaccine effectiveness. Such knowledge is vital for the future design of optimal vaccination strategies in the ageing population. [ABSTRACT FROM AUTHOR]

Background: Previous studies showed that the fourth SARS-CoV-2 vaccine dose has a protective effect against infection, as well as against severe disease and death. This study aimed to examine whether knowledge of a high-level antibody after the third dose may reduce compliance to the fourth booster dose among healthcare workers (HCWs). Methods: We conducted a prospective cohort study among HCWs vaccinated with the first three doses at Rambam Healthcare Campus, a tertiary hospital in northern Israel. Participants underwent a serological test before the fourth booster vaccine was offered to all of them, with results provided to participants. The population was divided into two groups, namely those with antibodies below 955 AU/mL and those with 955 AU/mL and higher, a cutoff found protective in a previous study. Multiple logistic regression was carried out to compare the compliance to the fourth booster between the two groups, adjusted for demographic and clinical variables. Results: After adjusting for the confounding variables, the compliance was higher in those with antibody levels below 955 AU/mL (OR = 1.41, p = 0.05, 95% CI 1.10–1.96). In addition, male sex and age of 60 years and above were also associated with higher vaccination rates (OR = 2.28, p < 0.001, 95% CI 1.64–3.17), (OR = 1.14, p = 0.043, 95% CI 1.06–1.75), respectively. Conclusions: Knowledge of the antibody status may affect compliance with the booster dose. Considering waning immunity over time, reduced compliance may affect the protection of HCWs who declined the fourth dose. [ABSTRACT FROM AUTHOR]

Objectives: As the COVID-19 pandemic wanes, understanding maternal–fetal antibody transfer remains crucial for optimizing vaccination strategies. This study evaluates anti-SARS-CoV-2 antibody levels in amniotic fluid following maternal BNT162b2 mRNA vaccination and/or COVID-19 infection during early pregnancy, focusing on the first and second trimesters. Methods: A retrospective cohort study was conducted at a tertiary university-affiliated hospital, involving 149 pregnant women who underwent amniocentesis. Anti-SARS-CoV-2 spike IgG levels were measured in amniotic fluid samples. Participants were categorized based on vaccination and infection status: vaccine-only, infection-only, vaccine + infection, and no vaccine/infection. Correlations between antibody levels and the time since vaccination or infection were analyzed. Results: The vaccine + infection group had a higher proportion of positive antibody levels compared to the vaccine-only group (63.6% vs. 35.9%, p = 0.029). Median SARS-CoV-2 IgG levels were significantly higher in the vaccine + infection group (283.0 AU/mL) than in the vaccine-only group (64.1 AU/mL, p = 0.006). Women who received three vaccine doses had higher antibody levels and more positive antibody rates compared to those with one or two doses. A significant negative correlation was found between antibody levels and the interval since the last vaccine dose or infection. Conclusions: Our results indicate the presence of anti-SARS-CoV-2 antibodies in the amniotic fluid, reflecting antibody transfer during early pregnancy. However, a noticeable decrease in immunity was observed, as indicated by declining amniotic fluid antibody levels over time. Further studies are needed to determine the optimal timing and number of boosters required to protect against new variants of SARS-CoV-2. [ABSTRACT FROM AUTHOR]

To study the durability of neutralizing antibodies (NAbs) against ten SARS-CoV-2 variants among COVISHIELD vaccine recipients from Pune, India, 184 vaccinee samples with (pre-positives) or without (pre-negatives) prior antibody positivity were evaluated. To estimate NAb levels, a validated ten-plex MSD ACE2 neutralization assay was used. NAbs against Alpha, Beta, Delta, and Omicron/subvariants were assessed at 1 month (PD2-1) and 6 months (PD2-6) post-vaccination, post-booster dose, and 2 years (2Y) post-vaccination. In pre-negatives, the seropositivity declined from PD2-1 to PD2-6 for all variants (Omicron variants: 14–54% to 0%; non-Omicron variants: 66–100% to 8–44%). In pre-positives, the decline in seropositivity from PD2-1 to PD2-6 was seen only for Omicron variants (14–39%). At PD2-6, a significant reduction in NAb levels was observed in all vaccinees against all the variants. Irrespective of prior exposure, the diminished anti-variant antibody levels at PD2-6 increased significantly following the administration of the booster. In conclusion, the COVISHIELD vaccine booster dose did provide cross-neutralizing antibodies against broad-range SARS-CoV-2 variants with improved durability up to [16 (15–18)] months post-booster dose and two years post-vaccination. [ABSTRACT FROM AUTHOR]

A phase 1–2, prospective, multicenter, randomized, open-label clinical trial (Code RPCEC00000382), with parallel groups, involving 1161 participants, was designed to assess the safety and immunogenicity of two Cuban COVID-19 vaccines (Mambisa and Abdala) in boosting COVID-19 immunity of convalescent adults after receiving one dose of either vaccine. The main safety outcome was severe vaccination adverse events occurring in <5% of vaccinees. Main immunogenicity success endpoints were a ≥4-fold anti-RBD IgG seroconversion or a ≥20% increase in ACE2-RBD inhibitory antibodies in >55% of vaccinees in Phase 1 and >70% in Phase 2. Neutralizing antibody titers against SARS-CoV-2 variants were evaluated. Both vaccines were safe—no deaths or severe adverse events occurred. Mild intensity adverse events were the most frequent (>73%); headaches predominated for both vaccines. Phase 1 responders were 83.3% (p = 0.0018) for Abdala. Mambisa showed similar results. Phase 2 responders were 88.6% for Abdala (p < 0.0001) and 74.2% for Mambisa (p = 0.0412). In both phases, anti-RBD IgG titers, inhibition percentages and neutralizing antibody titers increased significantly after the booster dose. Both vaccines were safe and their immunogenicity surpassed the study endpoints. [ABSTRACT FROM AUTHOR]

Background With coronavirus disease 2019 (COVID-19) vaccination no longer mandated by many businesses/organizations, it is now up to individuals to decide whether to get any new boosters/updated vaccines going forward. Methods We developed a Markov model representing the potential clinical/economic outcomes from an individual perspective in the United States of getting versus not getting an annual COVID-19 vaccine. Results For an 18–49 year old, getting vaccinated at its current price ($60) can save the individual on average $ 30–$603 if the individual is uninsured and $4–$437 if the individual has private insurance, as long as the starting vaccine efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is ≥50% and the weekly risk of getting infected is ≥0.2%, corresponding to an individual interacting with 9 other people in a day under Winter 2023–2024 Omicron SARS-CoV-2 variant conditions with an average infection prevalence of 10%. For a 50–64 year old, these cost-savings increase to $111–$1278 and $119–$1706 for someone without and with insurance, respectively. The risk threshold increases to ≥0.4% (interacting with 19 people/day), when the individual has 13.4% preexisting protection against infection (eg, vaccinated 9 months earlier). Conclusions There is both clinical and economic incentive for the individual to continue to get vaccinated against COVID-19 each year. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) continues to be a global health concern, and booster doses are necessary for maintaining vaccine-mediated protection, limiting the spread of severe acute respiratory syndrome coronavirus 2. Despite multiple COVID-19 vaccine options, global booster uptake remains low. Reactogenicity, the occurrence of adverse local/systemic side effects, plays a crucial role in vaccine uptake and acceptance, particularly for booster doses. We conducted a targeted review of the reactogenicity of authorized/approved messenger RNA (mRNA) and protein-based vaccines demonstrated by clinical trials and real-world evidence. It was found that mRNA-based boosters show a higher incidence and an increased severity of reactogenicity compared with the Novavax protein-based COVID-19 vaccine (NVX-CoV2373). In a recent study from the National Institute of Allergy and Infectious Diseases, the incidence of pain/tenderness, swelling, erythema, fatigue/malaise, headache, muscle pain, or fever was higher in individuals boosted with BNT162b2 (0.4% to 41.6% absolute increase) or mRNA-1273 (5.5% to 55.0% absolute increase) compared with NVX-CoV2373. Evidence suggests that NVX-CoV2373, when utilized as a heterologous booster, demonstrates less reactogenicity compared with mRNA vaccines, which, if communicated to hesitant individuals, may strengthen booster uptake rates worldwide. Clinical Trials Registration NCT04889209. [ABSTRACT FROM AUTHOR]

Socio-economic status (SES) disparities exist in the uptake of COVID-19 vaccination; however, most studies were conducted during the initial pandemic wave when vaccination was less discretionary, limiting generalizability. We aimed to determine whether differences in vaccination uptake across SES strata widened after the removal of vaccination-differentiated measures prior to the rollout of the second boosters, in a nationwide cohort of older Singaporeans at higher risk of severe-COVID-19. Retrospective population-based cohort study. Retrospective population-based cohort study of all Singaporeans aged ≥60 years from 22nd February 2021–14th February 2023. Cox regression models controlling for demographics and comorbidities were used to estimate hazard-ratios (HRs) for the uptake of primary vaccination as well as first/second boosters, as recorded in the national vaccination registry, according to SES (housing type). 836,170 individuals were included for completion of a primary vaccine series; 784,938 individuals for completion of the first booster and 734,206 individuals for the completion of the second booster. Differences in vaccination uptake by SES strata were observed (e.g. vaccination uptake in lowest-SES [1–2 room public-housing] versus highest-SES [private housing]: second booster, 47.6% vs. 58.1%; first booster, 93.9% vs. 98.0%). However, relative differences did not markedly widen during second booster rollout when vaccination was more discretionary (e.g. amongst those aged 60–69 years: 0.75 [95% CI = 0.73–0.76] for the first booster; 0.81 [95% CI = 0.79–0.84] for the second booster). While differences in vaccination uptake across SES strata by housing type persisted during the rollout of primary vaccination and subsequent boosters in a nationwide cohort of older Singaporeans, differences did not widen substantially when vaccination was made more discretionary. [ABSTRACT FROM AUTHOR]

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Adolescents are vulnerable to Coronavirus disease 2019 (COVID-19) infections; thus, their antibodies should be maintained above the protective value. This study aimed to evaluate the immune response and safety to the SARS-CoV-2 protein subunit recombinant vaccine (IndoVac®) as a heterologous booster dose against COVID-19 in Indonesian adolescents. This open-label prospective intervention study enrolled 150 clinically healthy adolescents aged 12–17 years who had received complete primary doses of the CoronaVac® vaccine from Garuda Primary Care Centres in Bandung City. The result of immunogenicity was presented with a 95% confidence interval (CI) and analyzed with t-tests from 14 days and 3, 6, and 12 months. The neutralizing antibody geometric mean titers (GMTs) (IU/mL) at baseline and 14 days after booster dose were 303.26 and 2661.2, respectively. The geometric mean fold rises (GMFR) at 3, 6, and 12 months after booster dose were 6.67 (5.217–8.536), 3.87 (3.068–4.886), and 2.87 (2.232–3.685), respectively. Both the neutralizing antibody and IgG antibody were markedly higher in the adolescents than in the adults at every timepoint. The incidence rate of adverse effects (AEs) until 28 days after booster dose was 82.7%, with a higher number of local events reported. Most reported solicited AEs were local pain followed by myalgia with mild intensity. Unsolicited AEs varied with each of the incidence rates < 10%, mostly with mild intensity. Adverse events of special interest (AESI) were not observed. At the 12-month follow-up after the booster dose, four serious adverse events (SAEs) not related to investigational products and research procedures were noted. This study showed that IndoVac® has a favorable immunogenicity and safety profile as a booster in adolescents and that the antibody titer decreases over time. [ABSTRACT FROM AUTHOR]

Stage I of this study (NCT04142242) demonstrated the safety and immunogenicity of a booster dose of a licensed quadrivalent meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT) and immune persistence 3 and 6–7 years after priming in older adults who received either quadrivalent meningococcal polysaccharide vaccine (MPSV4) or MenACYW-TT at ≥56 years of age. Stage II, reported here, assessed the antibody persistence after MenACYW-TT versus MPSV4 priming and the safety and immunogenicity of a booster dose of MenACYW-TT in older adults 5 years after primary vaccination with either MPSV4 or MenACYW-TT. A serum bactericidal assay (hSBA) was used to measure functional antibodies against each serogroup immediately before MenACYW-TT booster vaccination and on day (D) 30 post-booster. Safety was also assessed. Antibody persistence declined 5 years post-primary vaccination, with seroprotection (hSBA titer ≥1:8) rates trending higher in MenACYW-TT- versus MPSV4-primed participants. A robust immune response for all four serogroups was observed on D30 after the MenACYW-TT booster, with higher geometric mean titers and seroprotection rates in MenACYW-TT- versus MPSV4-primed participants. Safety outcomes were similar between the two groups. A single booster dose of MenACYW-TT was well tolerated and immunogenic in older adults, with a higher immune response observed in those primed with MenACYW-TT.

This phase 1, open-label, dose-escalation, multi-center study (NCT05477186) assessed the safety and immunogenicity of a booster dose of an mRNA COVID-19 vaccine (CV0501) encoding the SARS-CoV-2 Omicron BA.1 spike protein. Participants aged ≥ 18 years previously vaccinated with ≥ 2 doses of an mRNA COVID-19 vaccine received CV0501 doses ranging from 12 to 200 μg. After assessment of safety and immunogenicity of the 12 μg dose in 30 adults, 30 adults ≤ 64 years were randomized to receive either a 3 or 6 μg dose. Solicited adverse events (AEs) were collected for 7 days, unsolicited AEs for 28 days, and serious AEs (SAEs), medically attended AEs (MAAEs), and AEs of special interest (AESIs) until day (D) 181 post-vaccination. Serum neutralizing titers specific to SARS-CoV-2 BA.1, wild-type, Delta, and additional Omicron subvariants were assessed at D1, D15, D29, D91, and D181. Of 180 vaccinated participants (mean age: 49.3 years; 57.8% women), 70.6% had prior SARS-CoV-2 infection. Most solicited local (98.1%) and systemic (96.7%) AEs were of mild-to-moderate severity; the most common were injection site pain (57.5%; 33.3–73.3% across groups) and myalgia (36.9%; 13.3–56.7%). Unsolicited AEs were reported by 14.4% (6.7–26.7%) of participants (mild-to-moderate severity in 88.5% of the participants). Three participants (1.7%) reported SAEs, 16.7% (6.7–30.0%) reported MAAEs, and 8.3% (0.0–13.3%) reported AESIs (15 COVID-19 cases), none related to vaccination. Geometric means of serum neutralizing titers increased from baseline to D15 and D29 (dose-dependent), and then decreased over time. The safety and immunogenicity results supported advancement to a phase 2 trial.

Two vaccines are available to prevent serogroup B meningococcal disease, i.e. the four-component meningococcal serogroup B vaccine (4CMenB) and the bivalent-factor-H-binding-protein meningococcal serogroup B vaccine (MenB-fHbp). Currently, 4CMenB is offered as part of routine infant immunization schedules. Available immunogenicity data showed a progressive decline in protective serum bactericidal antibodies (SBA) titers, with a re-enhancement following a booster dose during infancy. Responses did not seem to be long-lasting and vaccinated individuals might be at risk of meningococcal diseases duriṇg adolescence. Only one study evaluated the possibility to administer a single booster dose to immunocompetent adolescents who received a primary series during infancy. Despite a high proportion of enrollees achieving protective SBA levels 28 days post-booster, titers tended to decrease 1 year after. Immunocompetent adolescents who received a primary series and a booster during the first two years of life might rather benefit from re-vaccination against MenB; current evidence does not support the possibility of a booster.

Background Underlying causes of vaccine hesitancy could significantly affect successful uptake of the SARS-CoV2 vaccine booster doses during new waves of COVID-19. Booster rates among US adults are far below what is needed for immunity, but little is known about booster hesitancy among fully vaccinated adults and whether medical mistrust exacerbates barriers to uptake.Methods A cross-sectional survey was completed among 119 adults in Philadelphia, PA who reported having received the primary SARS-CoV2 vaccine series but not a booster dose. Using the LaVeist Medical Mistrust (MM) Index, a k-means cluster analysis showed two clusters (Low MM, High MM) and differences in attitudes and perceptions about COVID-19 booster vaccines were assessed using F-tests.Results Respondents were 62% Black and female; mean age was 41; 46% reported earning less than $25,000 and 53% had a high school education or less. Overall intention to get boosted was low (mean 3.3 on 0-10 scale). Differences in COVID-19 booster perceptions between those with High (n = 56) vs. Low (n = 59) MM were found, independent of any demographic differences. Most statements (7/10) related to reasons to not be boosted were significant, with those with High MM indicating more concern about feeling sick from the vaccine (F=-3.91, p≤ .001), beliefs that boosters are ineffective for vaccinated people (F= −3.46, p≤ .001), and long-term side effect worries (F=-4.34, p≤ .001). Those with High MM were also more concerned about the adverse effects of the vaccine (F=-2.48, p=.02), but were more likely to trust getting information from doctors or healthcare providers (F= −2.25, p=.03).Conclusions Results indicate that medical mistrust is an important independent construct when understanding current COVID-19 booster hesitancy. While much work has looked at demographic differences to explain vaccine hesitancy, these results suggest that further research into understanding and addressing medical mistrust could be important for implementing interventions to increase booster rates.

We administered a questionnaire to participants who received different vaccination regimens to evaluate the effectiveness of Ad5-vectored COVID-19 vaccines. The results showed that administration of intramuscular Ad5-nCoV provided 21.32% more protection against SARS-CoV-2 infection than that of the inactivated COVID-19 vaccine in people who had received only one type of COVID-19 vaccine. Furthermore, aerosolized Ad5-nCoV exhibited good protection, whether it was administered as a homologous booster to people vaccinated with the intramuscular Ad5-nCoV or as a heterologous booster to people vaccinated with inactivated COVID-19 vaccines. Our research indicates that Ad5-nCoV is an effective booster. This finding supports the future selection of COVID-19 immunization strategies.

The BOOST (Booster promotion for older outpatients using SMS text reminders) program at Taipei Veterans General Hospital assessed the effectiveness of text message reminders in enhancing COVID-19 booster vaccination rates among the elderly, guided by the Health Belief Model (HBM). Targeting patients aged 65 and above, eligible yet unvaccinated for a COVID-19 booster, this cohort study sent personalized reminders a week prior to their scheduled appointments between April 18, 2022, and May 12, 2022, acting as cues to action to enhance vaccination uptake by overcoming perceived barriers and raising awareness of benefits. Over 5 weeks, the study observed a 38% increase in vaccination rate among 3,500 eligible patients, markedly surpassing the concurrent national rate increase of 4% for the same demographic. The majority of vaccinations occurred within two weeks after the reminder, illustrating the effectiveness of the strategy. Cox regression analysis identified age and time since last vaccination as significant predictors of responsiveness, with those aged 65–74 and 75–84 showing higher uptake, particularly when reminders were sent within 4 months after the last dose. A single reminder proved to be effective. The findings of this study demonstrate the potential of SMS reminders to promote COVID-19 vaccination among the elderly through the strategic use of HBM principles, suggesting a feasible and effective approach to public health communication.

ABSTRACTIndividuals who have Long COVID may have unique perspectives about COVID-19 vaccination due to the significant impact that COVID-19 has had on their lives. However, little is known about the specific vaccination perspectives among this patient population. The goal of our study was to improve our understanding of perspectives about COVID-19 vaccines among individuals with Long COVID. Interviews were conducted with patients receiving care at a post-COVID recovery clinic. Deductive thematic analysis was used to characterize participant perspectives according to the vaccine acceptance continuum framework, which recognizes a spectrum from vaccine acceptance to refusal. From interviews with 21 patients, we identified perspectives across the continuum of vaccine acceptance. These perspectives included acceptance of vaccines to prevent future illness, concerns about vaccine side effects on Long COVID symptoms, and refusal of vaccines due to perceived natural immunity. A limitation of our study is that these perspectives are specific to individuals receiving care at one post-COVID recovery clinic. In conclusion, our study demonstrates that some patients with Long COVID are uncertain about COVID-19 vaccines and boosters but may also be amenable to conversations that impact future vaccination acceptance. Patient perspectives should be considered when communicating recommendations for COVID-19 vaccinations to this population.

ABSTRACTWe sought in-depth understanding on the evolution of factors influencing COVID-19 booster dose and bivalent vaccine hesitancy in a longitudinal semi-structured interview-based qualitative study. Serial interviews were conducted between July 25th and September 1st, 2022 (Phase I: univalent booster dose availability), and between November 21st, 2022 and January 11th, 2023 (Phase II: bivalent vaccine availability). Adults (≥18 years) in Canada who had received an initial primary series and had not received a COVID-19 booster dose were eligible for Phase I, and subsequently invited to participate in Phase II. Twenty-two of twenty-three (96%) participants completed interviews for both phases (45 interviews). Nearly half of participants identified as a woman (n = 11), the median age was 37 years (interquartile range: 32–48), and most participants were employed full-time (n = 12); no participant reported needing to vaccinate (with a primary series) for their workplace. No participant reported having received a COVID-19 booster dose at the time of their interview in Phase II. Three themes relating to the development of hesitancy toward continued vaccination against COVID-19 were identified: 1) effectiveness (frequency concerns; infection despite vaccination); 2) necessity (less threatening, low urgency, alternate protective measures); and 3) information (need for data, contradiction and confusion, lack of trust, decreased motivation). The data from interviews with individuals who had not received a COVID-19 booster dose or bivalent vaccine despite having received a primary series of COVID-19 vaccines highlights actionable targets to address vaccine hesitancy and improve public health literacy.

ObjectivePakistan has been seriously affected by the COVID-19 pandemic, with numerous waves of infection. Using different vaccine and booster doses was a key component to control and combat this pandemic. This study aims to monitor the heterologous and homologous booster vaccination doses that generate immune responses in healthy adults after 9 months of vaccination.MethodsIn this cross-sectional, observational study a total of 173 samples were collected. Participants from both genders (Male and Female) between the ages of 18 to 25 years were enrolled for the study. Participants who had booster shots of homologous Sinopharm BBIBP CorV and heterologous Pfizer-BioNTech vaccines were included only, with the use of a Roche Cobas-e601 analyzer, the antibody titers in the blood serum were quantified by the ECLIA method. IBM SPSS 22 was utilized for descriptive statistical analysis and P< 0.05 was considered significant.ResultsIn this study the IgG antibody levels were measured against the full length of receptor binding domain (RBD) of the spike (S) protein. The mean antibody titer in the Pfizer group was 9764 ± 10976 U/mL and 5762 ± 4302 U/mL in the Sinopharm group. The Mean IgG antibody levels of the Pfizer-vaccinated group were significantly higher than the Sinopharm-vaccinated group (P=0.000, each). Comparing the Sinopharm BBIBP CorV booster dosage to the Pfizer booster, Pfizer BNT162b2demonstrated a stronger immune response. However, there were no immunological gender-specific significant differences. The administration of a third dosage of Pfizer BNT162b2 after two doses of BBIBP CorVConclusionThe administration of a third dosage of Pfizer BNT162b2 after two doses of BBIBP-CorV is recommended to boost the humoral immune response in the general population while there was no gender-specific difference observed. More effectiveness can be attained by administering additional doses due to the antibody decay.

This article proposed a technique for a low‐power and fast start‐up voltage‐controlled oscillator (VCO) for a high data rate 5 G New Radio (5G‐NR) application. The 5G‐NR high data rate signals require a fast start‐up VCO to accommodate the short pulse width. In this proposed work, a cross‐coupled pair (XCP) is integrated with a center‐tapped orthogonal symmetry inductor placed at the gates of the XCP, forming an inductive booster VCO (IBVCO). The inductive impedance at the gate of the XCP preserve the symmetry signal profile of the output voltage swing while alleviating the intrinsic parasitic capacitance effect and flicker noise effect of the transistor under the absence of the tail current source. The concept proves with the improvement on the phase noise performance and generating a fast start‐up without affecting the VCO bandwidth. The VCO also provides the enhancement of the output voltage swing under low power consumption. The IBVCO has been fabricated in 180 nm complementary metal oxide semiconductor technology and consumes a minimum area of only 0.7 mm2. The IBVCO achieved a 13% tuning range from 3.3 to 3.75 GHz bandwidth with a supply voltage, VDD of 0.7 V. The total power consumption is 1 mW with a corresponding phase noise of −122.60 dBc/Hz and a Figure of Merit (FoM) of 193.48 dBc/Hz at 3.52 GHz carrier center frequency at 1 MHz offset. The start‐up time of the VCO achieved is 5 ns. [ABSTRACT FROM AUTHOR]

Rabies is a highly virulent viral disease that has been associated with large-scale population declines of the endangered African wild dog (Lycaon pictus). Rabies vaccination may be a valuable conservation tool in this species, but studies indicate that a single dose does not always confer protective immunity. We examined 47 serum samples from 22 captive African wild dogs (sampled opportunistically for other purposes) to assess whether serum antibody levels after vaccination correlated with the number of doses received and whether other factors affected outcomes. Results of the fluorescent antibody virus neutralization test showed that median antibody titers were 0.085 IU/mL prevaccination, 0.660 IU/mL after a single vaccination, and 22.150 IU/mL after a booster vaccination. Antibody titers above 0.5 IU/mL, internationally accepted as the threshold for seroconversion, were found in none of the samples taken prevaccination, 66.67% of samples taken after primary vaccination, and 90.90% of samples collected after booster vaccination. This study illustrates the probable protective benefit a rabies booster vaccination may provide in African wild dogs and serves as a basis for future research to improve vaccination protocols contributing to the conservation of this endangered species. [ABSTRACT FROM AUTHOR]

Background and Aims: Coronavirus disease 2019 (COVID‐19) has become a global pandemic and led to increased mortality and morbidity. Vaccines against the etiologic agent; severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) were approved for emergency use on different platforms. In the early phase of the pandemic, Thai healthcare workers (HCWs) received CoronaVac, an inactivated vaccine, as the first vaccine against SARS‐CoV‐2, followed by ChAdOx1 nCoV‐19, a viral vector‐based vaccine, or BNT162b2, an mRNA vaccine, as a booster dose. This preliminary study evaluated the immunogenicity of ChAdOx1 nCoV‐19 and BNT162b2 as a booster dose in HCWs who previously received two doses of CoronaVac. Methods: Ten HCW participants received ChAdOx1 nCoV‐19 and another 10 HCWs received BNT162b2 as a booster dose after two doses of CoronaVac. Anti‐RBD IgG, neutralizing antibodies (NAb), and cellular immunity, including interferon‐gamma (IFN‐γ)‐releasing CD4, CD8, double negative T cells, and NK cells, were measured at 3 and 5 months after the booster dose. Results: There was no significant difference in anti‐RBD IgG levels at 3 and 5 months between the two different types of booster vaccine. The levels of anti‐RBD IgG and NAb were significantly decreased at 5 months. HCWs receiving BNT162b2 had significantly higher NAb levels than those receiving ChAdOx1 nCoV‐19 at 5 months after the booster dose. IFN‐γ release from CD4 T cells was detected at 3 months with no significant difference between the two types of booster vaccines. However, IFN‐γ‐releasing CD4 T cells were present at 5 months in the ChAdOx1 nCoV‐19 group only. Conclusion: ChAdOx1 nCoV‐19 or BNT162b2 can be used as a booster dose after completion of the primary series primed by inactivated vaccine. Although the levels of immunity decline at 5 months, they may be adequate during the first 3 months after the booster dose. [ABSTRACT FROM AUTHOR]

Participants in studies investigating COVID-19 vaccines commonly report reactogenicity events, and concerns about side effects may lead to a reluctance to receive updated COVID-19 vaccinations. A real-world, post hoc analysis, observational 2019nCoV-406 study was conducted to examine reactogenicity within the first 2 days after vaccination with either a protein-based vaccine (NVX-CoV2373) or an mRNA vaccine (BNT162b2 or mRNA-1273) in individuals who previously completed a primary series. Propensity score adjustments were conducted to address potential confounding. The analysis included 1130 participants who received a booster dose of NVX-CoV2373 (n = 303) or an mRNA vaccine (n = 827) during the study period. Within the first 2 days after vaccination, solicited systemic reactogenicity events (adjusted) were reported in 60.5% of participants who received NVX-CoV2373 compared with 84.3% of participants who received an mRNA vaccine; moreover, 33.9% and 61.4%, respectively, reported ≥3 systemic reactogenicity symptoms. The adjusted mean (95% CI) number of systemic symptoms was 1.8 (1.6–2.0) and 3.2 (3.0–3.4), respectively. Local reactogenicity events (adjusted) were reported in 73.4% and 91.7% of participants who received NVX-CoV2373 and mRNA vaccines, respectively; the adjusted mean (95% CI) number of local symptoms was 1.5 (1.33–1.61) and 2.4 (2.31–2.52), respectively. These results support the use of adjuvanted, protein-based NVX-CoV2373 as an immunization option with lower reactogenicity than mRNAs. [ABSTRACT FROM AUTHOR]

We report neutralization titer data against contemporary SARS-CoV-2 sublineages from an ongoing, phase 2/3, open-label, clinical trial of a single dose (30 μg) of an Omicron XBB.1.5-adapted BNT162b2 monovalent mRNA vaccine. The trial included healthy participants who had received at least three previous doses of an mRNA vaccine authorized in the United States, with the most recent authorized vaccine dose being a bivalent Omicron BA.4/BA.5-adapted vaccine given at least 150 days before the study vaccination. In this analysis, Omicron XBB.1.5, BA.2.86, and JN.1 serum neutralizing titers were assessed at baseline and at 1 month after vaccination. Analyses were conducted in a subset of participants who were at least 18 years of age (N = 40) and who had evidence of previous SARS-CoV-2 infection. Immunogenicity was also evaluated in a group of participants who received bivalent BA.4/BA.5-adapted BNT162b2 in another study (ClinicalTrials.gov Identifier: NCT05472038) and who were matched demographically to the participants in the current trial. In this analysis, monovalent XBB.1.5-adapted BNT162b2 vaccine elicited higher XBB.1.5, BA.2.86, and JN.1 neutralizing titers than those elicited by bivalent BA.4/BA.5-adapted BNT162b2. Overall geometric mean fold rises in neutralizing titers from baseline to 1 month after vaccination were higher among participants who received XBB.1.5-adapted BNT162b2 than those who received bivalent BA.4/BA.5-adapted BNT162b2 for XBB.1.5 (7.6 vs. 5.6), slightly higher for JN.1 (3.9 vs. 3.5), and similar for BA.2.86 (4.8 vs. 4.9). ClinicalTrials.gov Identifier: NCT05997290. [ABSTRACT FROM AUTHOR]

We assessed the vaccination effectiveness (VE) of a COVID-19 booster vaccine dose and the association between morbidity and absenteeism with COVID-19 booster vaccine receipt among healthcare personnel (HCP) in 2022–2023 in Greece. We followed 5752 HCP from November 14, 2022 through May 28, 2023 for episodes of absenteeism. Absenteeism for non-infectious causes, pregnancy leave, or annual leave was not recorded. Full vaccination was defined as a primary vaccination series plus one booster dose within the past six months. Multivariable regression models were used to estimate the association of full COVID-19 vaccination with the outcomes of interest. A total of 1029 episodes of absenteeism occurred during the study period (17.9 episodes per 100 HCP). The mean duration of absence per episode was 5.2 days, and the total duration of absence was 5237 days. COVID-19 was diagnosed in 736 (12.8 %) HCP, asymptomatic SARS-CoV-2 infection in 62 (1.1 %) HCP, and influenza in 95 (1.7 %) HCP. Overall, COVID-19, influenza, and asymptomatic SARS-CoV-2 infection accounted for 71.5 %, 9.2 %, and 6.0 % of episodes of absenteeism, respectively. Multivariable regression models indicated that fully vaccinated HCP were absent from work for shorter periods [adjusted odds ratio (aOR): 0.42; 95 % confidence interval (CI): 0.21–0.83], were less likely to develop COVID-19 [aOR: 0.37; 95 % CI: 0.17–0.81)], and were more likely to develop an asymptomatic SARS-CoV-2 infection (aOR: 5.90; 95 % CI: 1.27–27.45). The adjusted full VE against COVID-19 was 62.8 % (95 % CI: 18.6 %-83.0 %). COVID-19 remains a significant cause of morbidity and absenteeism among HCP. Full COVID-19 vaccination status conferred significant protection against COVID-19 and was associated with shorter periods of absence from work. [ABSTRACT FROM AUTHOR]

As solid organ transplant (SOT) recipients remain at risk of severe outcomes after SARS-CoV-2 infections, vaccination continues to be an important preventive measure. In SOT recipients previously vaccinated with at least three doses of BNT162b2, we investigated humoral responses to BNT162b2 booster doses. Anti-SARS-CoV-2 receptor binding domain (RBD) immunoglobulin G (IgG) was measured using an in-house ELISA. Linear mixed models were fitted to investigate the change in the geometric mean concentration (GMC) of anti-SARS-CoV-2 RBD IgG after vaccination in participants with intervals of more or less than six months between the last two doses of vaccine. We included 107 SOT recipients vaccinated with a BNT162b2 vaccine. In participants with an interval of more than six months between the last two vaccine doses, we found a 1.34-fold change in GMC per month (95% CI 1.25–1.44), while we found a 1.09-fold change in GMC per month (95% CI 0.89–1.34) in participants with an interval of less than six months between the last two vaccine doses, resulting in a rate ratio of 0.82 (95% CI 0.66 to 1.01, p = 0.063). In conclusion, the administration of identical COVID-19 mRNA vaccine boosters within six months to SOT recipients may result in limited humoral immunogenicity of the last dose. [ABSTRACT FROM AUTHOR]

Background Protection against contemporary severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants requires sequence-adapted vaccines. Methods In this ongoing phase 2/3 trial, 12–17-year-olds (n = 108), 18–55-year-olds (n = 313), and >55-year-olds (n = 306) who previously received 3 original BNT162b2 30-µg doses, received a fourth dose (second booster) of 30-µg bivalent original/Omicron-BA.4/BA.5-adapted BNT162b2 (BNT162b2-Omi.BA.4/BA.5). For comparisons with original BNT162b2, participants were selected from another phase 3 trial. Immunologic superiority 1 month after vaccination, with respect to 50% neutralizing titers (lower bound [LB] of 2-sided 95% confidence interval [CI] for geometric mean ratio [GMR], >1), and noninferiority with respect to seroresponse rates (LB of 2-sided 95% CI for rate difference, greater than −5%), for Omicron BA.4/BA.5 were assessed in >55-year-olds versus original BNT162b2 as a second booster. Noninferiority with respect to neutralizing titer level (LB of 2-sided 95% CI for GMR, > 0.67) and seroresponse rate (LB of 2-sided 95% CI for rate difference, greater than −10%) of Omicron BA.4/BA.5 immune response for BNT162b2-Omi.BA.4/BA.5 in 18–55 versus >55-year-olds was assessed. Results One month after vaccination in >55-year-olds, the model-adjusted GMR of Omicron BA.4/BA.5 neutralizing titers for the BNT162b2-Omi.BA.4/BA.5 versus BNT162b2 groups (2.91 [95% CI, 2.45–3.44]) demonstrated the superiority of BNT162b2-Omi.BA.4/BA.5. Adjusted difference in the percentages of >55-year-olds with seroresponse (26.77% [95% CI, 19.59–33.95]) showed noninferiority of BNT162b2-Omi.BA.4/BA.5 to BNT162b2. Noninferiority of BNT162b2-Omi.BA.4/BA.5 in 18–55-year-olds compared with >55-year-olds was met for model-adjusted GMR and seroresponse. Geometric mean titers in 12–17-year-olds increased from baseline to 1 month after vaccination. The BNT162b2-Omi.BA.4/BA.5 safety profile was similar to the profiles for booster doses of bivalent Omicron BA.1-modified BNT162b2 and original BNT162b2 reported in previous studies. Conclusions Based on immunogenicity and safety data up to 1 month after vaccination in participants who previously received 3 original BNT162b2 doses, a BNT162b2-Omi.BA.4/BA.5 30-µg booster has a favorable benefit-risk profile. Clinical Trials Registration NCT05472038 [ABSTRACT FROM AUTHOR]