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Objective: The purpose of this study was: (a) to determine COVID-19 vaccination rates among college students, (b) to assess what proportion of college students self-report currently or previously having COVID-19, and (c) to test theory of planned behavior (TPB)-based constructs in predicting the COVID-19 booster vaccination behavioral intentions. Methods: A non-experimental, cross-sectional study design was applied. Participants: The sample consisted of 288 college students ages 18 years and older. Results: The stepwise multiple regression revealed that attitude (β =.329; p <.001) and subjective norm (β =.244; p <.001) were statistically significant predictors of intention to receive the COVID-19 booster, accounting for 86.7% (Adjusted R2 =.867, F (2, 204 = 673.002, p <.001) of the variance. Conclusions: College students are at high risk for more severe complications of COVID-19 infection due to low vaccination rates. The instrument designed for this study may be used to design TPB-based interventions to increase COVID-19 vaccination and booster intentions of college students. [ABSTRACT FROM AUTHOR]

Background: The SARS-CoV-2 Omicron variant, since its initial detection, has rapidly spread across the globe, becoming the dominant strain. It is important to study the immune response of SARS-CoV-2 Omicron variant due to its remarkable ability to escape the majority of existing SARS-CoV-2 neutralizing antibodies. The surge in SARS-CoV-2 Omicron infections among most Chinese residents by the end of 2022 provides a unique opportunity to understand immune system's response to Omicron in populations with limited exposure to prior SARS-CoV-2 variants. Methods: We tested the levels of IgG, IgA, and IgM specific to the prototype SARS-CoV-2 RBD (receptor-binding domain) in blood samples from 636 individuals by chemical luminescence assay, ELISA and pseudovirus-based neutralization assay. Results: Inoculation with inactivated prototype SARS-CoV-2 vaccines or recombinant protein vaccines showed higher IgG levels after infection than the unvaccinated individuals. Moreover, the age resulted in different IgG levels after the Omicron infection as IgG level of the patients aged > 60 years was lower than that of patients aged < 60 years. This indicates that the IgG induced by SARS-CoV-2 Omicron breakthrough infection was different between old and young individuals. We found that a booster dose of the prototype SARS-CoV-2 vaccine led to a significant increase in the neutralizing immune response against the prototype SARS-CoV-2 and helped induce neutralizing antibodies against BA.5 and BF.7 variants after an Omicron breakthrough infection in young individuals, which is different from a previous report on older people. Conclusions: These data suggest that the prototype SARS-CoV-2 booster vaccination helps induce high levels of neutralizing antibodies against Omicron BA.5 and BF.7 variants after Omicron breakthrough infection in young individuals. Trial registration: This study is a purely observational study. [ABSTRACT FROM AUTHOR]

The emergence of new variants and diverse vaccination regimens have raised uncertainty about vaccine effectiveness against SARS-CoV-2. This study aims to investigate the impact of Omicron primo-/reinfection and primary vaccination schedules on the immunogenicity of an mRNA-based booster dose over a six-month period. We conducted a prospective cohort study to assess the durability and level of antibodies of 678 healthcare workers fully vaccinated against COVID-19. They were categorized based on their primary vaccination regimen. Blood samples were collected before the booster dose and 1 and 6 months after. Significant Anti-S-RBD differences were found between previously infected and naïve volunteers (p = 0.01). Considering the initial vaccine schedules, mRNA-based vaccines displayed significant higher antibody production and longer persistence among both infected and naïve participants. After the booster dose, participants primoinfected with the Omicron variant exhibited higher antibody concentrations than those who experienced reinfection, even after 6 months of follow-up (22,545 and 9460 U/mL, respectively). Moreover, these groups showed the most pronounced disparity in antibody titers ratios between infected and uninfected individuals. Overall, the booster dose failed to enhance humoral response in individuals reinfected with the Omicron variant after receiving it. Hybrid immunity and mRNA-based vaccine initial schedules showed higher levels and longer persistence of 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]

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]

This research compares drivers of full COVID-19 vaccinations and booster doses across US counties. Booster doses are contingent upon primary doses being received, and the risk attitudes and propensities to get vaccinated may respond to different motivations across individuals, along with distinctions in the supply chain. Our results, obtained in a quantitative framework through fractional probit, logit and quantile regressions, show that new COVID cases do not significantly impact vaccinations, while supply chain aspects via doctors' visits have a positive impact. Income, race, age, and education also play a significant role. Further, political ideologies matter, while government decentralization does not. The differences in the effects across primary versus booster doses are discussed. [ABSTRACT FROM AUTHOR]

Abstract Background The SARS-CoV-2 Omicron variant, since its initial detection, has rapidly spread across the globe, becoming the dominant strain. It is important to study the immune response of SARS-CoV-2 Omicron variant due to its remarkable ability to escape the majority of existing SARS-CoV-2 neutralizing antibodies. The surge in SARS-CoV-2 Omicron infections among most Chinese residents by the end of 2022 provides a unique opportunity to understand immune system’s response to Omicron in populations with limited exposure to prior SARS-CoV-2 variants. Methods We tested the levels of IgG, IgA, and IgM specific to the prototype SARS-CoV-2 RBD (receptor-binding domain) in blood samples from 636 individuals by chemical luminescence assay, ELISA and pseudovirus-based neutralization assay. Results Inoculation with inactivated prototype SARS-CoV-2 vaccines or recombinant protein vaccines showed higher IgG levels after infection than the unvaccinated individuals. Moreover, the age resulted in different IgG levels after the Omicron infection as IgG level of the patients aged > 60 years was lower than that of patients aged

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.

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.

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 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 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.

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]

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]

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]

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]

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: 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]

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]

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]

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]

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]

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]

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]

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]

This study investigates fragments of the type last I heard/checked based on data from the Corpus of Contemporary American English , which shows a steep increase in frequency for this construction in recent decades. Syntactically, ' last I fragments' are disjuncts that are positionally mobile with respect to their host clause and their 'elliptical' form can be linked to different 'full' forms, viz. specificational sentences and temporal adjuncts. Functionally, their underlying evidential meaning gives rise to different, more specific discourse functions depending on contextual use: viz. downtoner, booster and ironic use. A comparison with unreduced (full) forms shows that these fragments are more likely to have evidential meaning, with reduced form thus acting as an important functional signal. Finally, it is argued that their grammatical status is best captured by a constructional account, which identifies them as constructionalizing units, rather than a simple ellipsis account. [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 Yellow fever (YF) is a mosquito-borne and recently re-emerging viral haemorrhagic fever endemic to sub-Saharan Africa and South America. A highly effective vaccine against YF is licensed and recommended as part of routine childhood immunisation as a single dose at 9 months. Recent observational data demonstrate waning immunity following single primary vaccination and suggest that children in endemic areas may require booster vaccination. Methods This open-label, non-randomised clinical vaccine trial (ClinicalTrials.gov, NCT05332197, registered on 31 March 2022, URL: https://clinicaltrials.gov/study/NCT05332197) will assess the safety and immunogenicity of a booster dose of the licensed 17D YF vaccine in Gambian children. The trial will recruit 750 children in three cohorts of different ages (250 each). All children were vaccinated with the 17D YF vaccine at 9–10 months of age as part of clinical trials run by the Medical Research Council (MRC) Unit The Gambia, and are thus well-characterised, including basic clinical, anthropometric, and post-primary immunogenicity data. The children will receive booster doses at 15 months, 4 years, or 8.5 years. Serum samples will be taken before and 28 days after the booster, with additional sampling for exploratory endpoints in subgroups. Adverse events are solicited for the first three days following vaccination and recorded throughout the study period. The primary objective of the trial is to describe the safety and immunogenicity of the booster in the different age cohorts. Secondary objectives are to characterise the rate of sero-reversion (change from seropositive to seronegative) over a period of 9 months to 8 years following single primary vaccination and to profile the immune response to the booster to explore underlying mechanisms for the longevity of vaccine-induced antibody. Discussion The results of this trial are likely to directly impact WHO recommendations on whether booster vaccination is required for children in endemic areas, and if so, the optimal timing of such a booster.

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.

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.

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.

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.

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.