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Breakthrough COVID-19 (occurring in fully vaccinated people) has been described. Data on its characteristics among immune-mediated rheumatic disease (IMRD) patients are scarce. This study describes breakthrough COVID-19 occurring in IMRD patients participating in the SAFER-study, a Brazilian multicentric cohort evaluating the safety, effectiveness, and immunogenicity of SARS-CoV-2 vaccines in patients with autoimmune diseases. A descriptive analysis of the population and a binary logistic regression model were performed to evaluate the predictors of COVID-19-related hospitalization. A p-value < 0.05 was significant. The included 160 patients were predominantly females (83.1%), with a mean (SD) age of 40.23 (13.19) years. The patients received two (19%), three (70%), or four (11%) vaccine doses. The initial two-dose series was mainly with ChAdOx1 (Oxford/AstraZeneca) (58%) or BBIBP-CorV (Sinopharm-Beijing) (34%). The first booster (n = 150) was with BNT162b2 (BioNtech/Fosun Pharma/Pfizer) (63%) or ChAdOx1 (29%). The second booster (n = 112) was with BNT162b2 (40%) or ChAdOx1 (26%). The COVID-19 hospitalization rate was 17.5%. IMRD moderate/high activity (OR: 5.84; CI: 1.9–18.5; p = 0.002) and treatment with corticosteroids (OR: 2.94; CI: 1.02–8.49; p = 0.0043) were associated with higher odds of hospitalization, while increasing the number of vaccine doses was protective (OR: 0.37; CI: 0.15–0.9; p = 0.032). These findings, along with previous reassuring results about the safety of the COVID-19 vaccines, argue in favor of booster vaccination in IMRD patients. [ABSTRACT FROM AUTHOR]

This is a retrospective observational study including all COVID-19 patients admitted at our Institute throughout three successive pandemic waves, from January 2021 to June 2023. The main in-hospital outcomes (clinical progression [CP], defined as admission to Intensive Care Unit [ICU]/death, and death within 28 days) were compared among participants unvaccinated (NV), fully vaccinated (FV), with one (FV&B1) and two (FV&B2) booster doses. Vaccinated participants were stratified into recently and waned FV/FV&B1/FV&B2, depending on the time elapsed from last dose (≤ and >120 days, respectively). There were 4488 participants: 2224 NV, 674 FV, 1207 FV&B1, and 383 FV&B2. Within 28 days, there were 604 ICU admissions, 396 deaths, and 737 CP. After adjusting for the main confounders, the risk of both in-hospital outcomes was reduced in vaccinated individuals, especially in those who received the booster dose (approximately by 36% for FV and >50% for FV&B1 and FV&B2 compared to NV). Similarly, after restricting the analysis to vaccinated participants only, we observed a risk reduction of approximately 40% for FV&B1 and 50% for FV&B2, compared to FV, regardless of the distance since the last dose. Our data confirm the vaccine's effectiveness in preventing severe COVID-19 and support the efforts to increase the uptake of booster doses, mainly among older and frailer individuals, still at a greater risk of clinical progression. [ABSTRACT FROM AUTHOR]

Abstract Objective This study aimed to investigate factors influencing the uptake of first and second COVID-19 booster vaccines among adults in Belgium, particularly age, sex, region of residence and laboratory confirmed COVID-19 infection history. Results A binomial regression model was used with having received the first or second booster as outcome and age, sex, region of residence and infection history as fixed variables. Among adults, there was generally a higher uptake to receive the first booster among older age groups compared to younger ones. Females, individuals residing in Flanders and those with no previous COVID-19 infection were more likely to receive the first booster. For the second booster, the same age trend was seen as for the first booster. Males, individuals residing in Flanders and those who tested positive for COVID-19 once after first booster were more likely to receive the second booster. Individuals with multiple positive COVID-19 tests before and after primary course or first booster were less likely to receive the subsequent booster dose compared to COVID-naïve individuals. This information could be used to guide future vaccination campaigns during a pandemic and can provide valuable insights into booster uptake patterns.

This is a retrospective observational study including all COVID-19 patients admitted at our Institute throughout three successive pandemic waves, from January 2021 to June 2023. The main in-hospital outcomes (clinical progression [CP], defined as admission to Intensive Care Unit [ICU]/death, and death within 28 days) were compared among participants unvaccinated (NV), fully vaccinated (FV), with one (FV&B1) and two (FV&B2) booster doses. Vaccinated participants were stratified into recently and waned FV/FV&B1/FV&B2, depending on the time elapsed from last dose (≤ and >120 days, respectively). There were 4488 participants: 2224 NV, 674 FV, 1207 FV&B1, and 383 FV&B2. Within 28 days, there were 604 ICU admissions, 396 deaths, and 737 CP. After adjusting for the main confounders, the risk of both in-hospital outcomes was reduced in vaccinated individuals, especially in those who received the booster dose (approximately by 36% for FV and >50% for FV&B1 and FV&B2 compared to NV). Similarly, after restricting the analysis to vaccinated participants only, we observed a risk reduction of approximately 40% for FV&B1 and 50% for FV&B2, compared to FV, regardless of the distance since the last dose. Our data confirm the vaccine’s effectiveness in preventing severe COVID-19 and support the efforts to increase the uptake of booster doses, mainly among older and frailer individuals, still at a greater risk of clinical progression.

Objective: This study aimed to investigate factors influencing the uptake of first and second COVID-19 booster vaccines among adults in Belgium, particularly age, sex, region of residence and laboratory confirmed COVID-19 infection history. Results: A binomial regression model was used with having received the first or second booster as outcome and age, sex, region of residence and infection history as fixed variables. Among adults, there was generally a higher uptake to receive the first booster among older age groups compared to younger ones. Females, individuals residing in Flanders and those with no previous COVID-19 infection were more likely to receive the first booster. For the second booster, the same age trend was seen as for the first booster. Males, individuals residing in Flanders and those who tested positive for COVID-19 once after first booster were more likely to receive the second booster. Individuals with multiple positive COVID-19 tests before and after primary course or first booster were less likely to receive the subsequent booster dose compared to COVID-naïve individuals. This information could be used to guide future vaccination campaigns during a pandemic and can provide valuable insights into booster uptake patterns. [ABSTRACT FROM AUTHOR]

Background: Waning of COVID-19 vaccine efficacy/effectiveness (VE) has been observed across settings and epidemiological contexts. We conducted a systematic review of COVID-19 VE studies and performed a meta-regression analysis to improve understanding of determinants of waning. Methods: Systematic review of PubMed, medRxiv and the WHO-International Vaccine Access Center database summarizing VE studies on 31 December 2022. Studies were those presenting primary adult VE data from hybrid immunity or third/fourth mRNA COVID-19 monovalent vaccine doses [due to limited data with other vaccines] against Omicron, compared with unvaccinated individuals or individuals eligible for corresponding booster doses but who did not receive them. We used meta-regression models, adjusting for confounders, with weeks since vaccination as a restricted cubic spline, to estimate VE over time since vaccination. Results: We identified 55 eligible studies reporting 269 VE estimates. Most estimates (180/269; 67 %) described effectiveness of third dose vaccination; with 48 (18 %) and 41 (15 %) describing hybrid immunity and fourth dose effectiveness, respectively, mostly (200; 74 %) derived from test-negative design studies. Most estimates (176/269; 65 %) reported VE compared with unvaccinated comparison groups. Estimated VE against mild outcomes declined following third dose vaccination from 62 % (95 % CI: 58 % – 66 %) after 4 weeks to 48 % (41 % – 55 %) after 20 weeks. Fourth dose VE against mild COVID-19 declined from 48 % (41 % – 56 %) after 4 weeks to 47 % (19 % – 65 %) after 20 weeks. VE for severe outcomes was higher and declined in the three-dose group from 90 % (87 % – 92 %) after 4 weeks to 70 % (65 – 74 %) after 20 weeks. Conclusions: Time-since vaccination is an important determinant of booster dose VE, a finding which may support seasonal COVID-19 booster doses. Integration of VE and immunological parameters – and longer-term data including from other vaccine types – are needed to better-understand determinants of clinical protection.

IntroductionIn the response to and prevention and control of the Novel coronavirus pneumonia, the COVID-19 vaccine does not provide lifelong immunity, and it is therefore important to increase the rate of booster shots of the COVID-19 vaccine. In the field of information health science, research has found that information frames have an impact in changing individual attitudes and health behaviors.ObjectiveThis study focuses on the effects of different influencing factors on the public’s willingness to receive the booster shots of the COVID-19 vaccine under two information frameworks.MethodsAn online questionnaire was conducted to explore the effects of demographic characteristics, personal awareness, social relationships, risk disclosure, perceived booster vaccination protection rate, and duration of protection under the assumption of an information framework. T test and one-way analysis were used to testing the effect of variables.Results(1) The persuasion effect under the gain frame is higher than that under the loss frame (B = 0.863 vs. B = 0.746); (2) There was no significant difference in subjects’ intention of booster vaccination in terms of gender, age, income, occupation, educational background and place of residence. Whether family members received booster vaccination was strongly correlated with their intention of vaccination under the loss framework (p = 0.017, M = 4.63, SD = 0.664). (3) The higher the understanding of COVID-19, the higher the degree of compliance with the government’s COVID-19 prevention and control measures, and the higher the willingness to strengthen vaccination; (4) Risk disclosure has a significant impact on people’s willingness to receive COVID-19 booster shots (M = 2.48, under the loss framework; M = 2.44, under the gain framework); (5) Vaccine protection rate and duration of protection have an impact on people’s willingness to vaccinate. Increased willingness to vaccinate when the protection rate of booster vaccine approaches 90% (M = 4.76, under the loss framework; M = 4.68, under the gain framework). When the vaccine protection period is 2 years, people are more willing to receive a booster vaccine; and the willingness to receive a booster shot is stronger under the loss framework (M = 4.60, SD = 0.721, p = 0.879).ConclusionThe impact of the information framework on COVID-19 vaccination intentions is different, and the disclosure of relevant health information should focus on the impact of the information framework and content on the public’s behavior toward strengthening vaccination. Therefore, in the face of public health emergencies, public health departments, healthcare institutions, and other sectors can consider adopting the Gainful Information Framework tool to disseminate health information to achieve better persuasion and promote public health behavior change enhancing public health awareness, and promoting universal vaccination.

Abstract Aims Patients with liver disease may exhibit higher infection rates and mortality rates from coronavirus disease 2019 (COVID‐19) than healthy individuals, and vaccination against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) is an effective prevention strategy. This meta‐analysis aimed to assess the effectiveness and safety of SARS‐CoV‐2 vaccines in patients with chronic liver disease (CLD) and post‐liver transplantation (LT). Methods The PubMed, Embase, and Cochrane databases were searched. A random‐effects model meta‐analysis was used to determine the seropositivity rates of SARS‐CoV‐2 antibodies, odds ratio (OR) compared with healthy controls (HC), risk ratio (RR) between the booster and standard vaccination regimen, and the rate of adverse reactions (ADR). Results In the standard vaccination regimen analysis, 17 controlled articles were included for effectiveness analysis, and six articles for ADR analysis. The pooled seropositivity rates of SARS‐CoV‐2 antibodies in patients with CLD and post‐LT were 93.3% (95% confidence interval [CI]: 89.0%–97.6%) and 69.1% (95% CI: 63.0%–75.3%), respectively. Both rates were lower than those in HC (p

Background : Solid organ transplant recipients exhibit decreased antibody responses, mainly due to their weakened immune systems. However, data are limited on antibody responses after the primary series of coronavirus disease 2019 (COVID-19) vaccines among recipients of various solid organ transplant types. Thus, we compared the antibody responses after three COVID-19 vaccine doses between liver transplant (LT) and kidney transplant (KT) recipients. Methods : We prospectively enrolled solid organ transplant recipients who received three COVID-19 vaccine doses from June 2021 to February 2022 and measured S1-specific immunoglobulin G antibodies using an enzyme-linked immunosorbent assay. Results : Seventy-six LT and 17 KT recipients were included in the final analysis. KT recipients showed consistently lower antibody responses even after the third vaccine dose (86.2% vs. 52.9%, P=0.008) and lower antibody titers (median, 423.0 IU/mL [interquartile range, 99.6–2,057 IU/mL] vs. 19.7 IU/mL [interquartile range, 6.9–339.4 IU/mL]; P=0.006) than were observed in LT recipients. Mycophenolic acid was a significant risk factor for a seropositive antibody response after the third vaccine dose in the multivariable analysis (odds ratio, 0.06; 95% confidence interval, 0.00–0.39; P=0.02). Conclusions: We found a weaker antibody response despite the completion of the primary series of COVID-19 vaccines in KT recipients than in LT recipients. Mycophenolic acid use in KT recipients might be the main contributor to this observation.

Objective: Unusual or unexpected effect of treatment Background: Herpes zoster is a condition in which there is reactivation of varicella zoster virus (VZV), which is usually seen in the elderly and those with immunocompromised states. Recently, however, there have been many reports of herpes zoster after administration of COVID-19 vaccines, although initial trials showed that these vaccines have good safety and immunogenicity profiles. At the time of writing, about 5 billion people worldwide had received their full course of COVID-19 vaccination. This case report describes an elderly man who developed herpes zoster after receiving a booster dose of the Pfizer-BioNTech (BNT162b2) vaccine, with no adverse effects after the first and second dose. Case Report: An 82-year-old man with underlying type 2 diabetes mellitus, hypertension, dyslipidemia, and cerebrovascular disease presented with left-sided chest and upper back pain. The pain was intermittent, burning in nature, and disturbed his sleep. A week prior to his presentation, he received a COVID-19 vaccine (BNT162b2) booster dose. Examination revealed multiple vesicles along his anterior and posterior T3 dermatome. He was diagnosed with herpes zoster and treated with a course of oral acyclovir. Upon review 7 days later, he had recovered well, with resolution of his vesicles and pain. Conclusions: COVID-19 vaccination remains an important measure to prevent transmission of infection and to reduce the mortality and morbidity caused by it. However, healthcare practitioners should be aware of the possible association between COVID-19 vaccination and herpes zoster. Appropriate explanation and safety advice on the possible adverse events following COVID-19 vaccination, including herpes zoster infection, should be given to patients. This will facilitate early recognition and treatment of this condition. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the efficacy of different COVID-19 booster vaccines by measuring the serum antibody titer. SARS-CoV-2 anti-nucleocapsid protein antibody (N-Ab), anti-spike protein antibody (S-Ab), and neutralizing antibody (Neut.Ab) were measured before and 4–6 weeks after booster vaccinations in healthcare personnel with a previous vaccination within 3–6 months. Personnel who previously received two doses of ChAdOx1 vaccine or two doses of BNT162b2 vaccine received the BNT162b2 vaccine (AAP and PPP groups, respectively). Personnel who previously received two doses of mRNA-1273 received the same vaccine as a booster dose (MMM group). Of the 917 participants, the AAP, MMM, and PPP groups comprised 837 (91.3%), 27 (2.9%), and 53 (5.8%) participants, respectively. The pre-booster S-Ab and Neut.Ab titer were significantly lower in the AAP group. After the booster vaccination, all participants were positive for S-Ab and Neut.Ab; furthermore, the S-Ab and Neut.Ab titer significantly increased in all three groups, although the post-booster S-Ab was lower in the AAP group than in the other groups. The post-booster Neut.Ab titer showed no significant difference among the groups. Our study's results suggest that booster vaccination, after two prior vaccinations, shows a significant effect regardless of the type of vaccine administered. [ABSTRACT FROM AUTHOR]

Background: The risk of fatal infection and death from Coronavirus disease 2019 (COVID-19) exposure increases in the elderly and those with coexisting illnesses such as cardiovascular disease, diabetes, cancer, obesity, and hypertension. The COVID-19 vaccine's efficacy and safety have been supported by numerous research. However, data from the Ministry of Health of Indonesia revealed that the elderly in North Jakarta had a reclining interest in receiving a booster dose. This research aimed to assess the perception of the elderly living in North Jakarta related to supporting and inhibiting factors in accepting the COVID-19 booster vaccination. Methods: This qualitative research used a grounded theory design. It was conducted from March to May 2022, and data were gathered in North Jakarta's numerous districts through in-depth interviews until saturation was reached. Furthermore, data were validated using member checking, source triangulation to families of elderly, and vaccination doctors. They were processed to produce transcripts, codes, and finalized themes. Results: Booster vaccination in the elderly was supported by 12 out of 15 informants, and the rest did not agree. The supporting factors include health, family, peer support, doctors, government, administrative requirements, endemic transformation, booster choice, and media coverage. Meanwhile, the inhibiting factors include hoaxes, concerns over the vaccine's safety and efficacy, political issues, family, and comorbidities. Conclusions: Most of the elderly displayed positive attitudes concerning booster shots, but it was discovered that some barriers need to be removed. [ABSTRACT FROM AUTHOR]

To determine the factors associated with not receiving the booster dose for COVID-19 in Peru, a cross-sectional study by secondary analysis of a University of Maryland and Facebook survey database assessing the global impact of COVID-19 was conducted. Data of Peruvian users of this social network over 18 years of age who answered the survey between 13 February 2022 and 14 April 2022 were analyzed. We evaluated the association between sociodemographic characteristics, comorbidities, and history of COVID-19 with having received a booster dose for COVID-19. Crude (cPR) and adjusted (aPR) prevalence ratios with their respective 95% confidence intervals (95%CI) were calculated. A sample of 20,814 adults, 21.5% of whom reported not receiving the booster dose, was analyzed. People under 75 years of age had a higher prevalence of not having received the booster dose. Likewise, having a university education (aPR = 1.03; 95%CI: 1.02–1.05), secondary, or pre-university education (aPR = 1.07; 95%CI: 1.05–1.09), or having a primary level or less (aPR = 1.11; 95%CI: 1.05–1.18), were associated with a higher prevalence of not receiving the booster, compared to individuals with a postgraduate education. Being employed (aPR = 1.01; 95%CI: 1.00–1.02), having had COVID-19 (aPR = 1.03; 95%CI: 1.01–1.04) and living in a town (aPR = 1.05; 95%CI: 1.02–1.07) or in a rural area (aPR = 1.06; 95%CI: 1.03–1.10), compared to living in the city, had a similar association. On the contrary, the female gender was associated with a lower prevalence of not receiving the booster (aPR = 0.97; 95%CI: 0.96–0.99). Sociodemographic characteristics and a history of having had COVID-19 were associated with the probability of not having received the booster dose for COVID-19 in the Peruvian population. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the mixed and homogeneous application of the inactivated SARS-CoV-2 vaccine CoronaVac (CV) and the mRNA vaccine BNT162b2 (BNT). This prospective cohort study included 235 health care workers who had received two prime shots with CoronaVac. They were divided into three cohorts after the third month: Cohort-I (CV/CV); Cohort-II (CV/CV/CV); and Cohort-III (CV/CV/BNT). Anti-S-RBD-IgG and total anti-spike/anti-nucleocapsid-IgG antibody concentrations were examined in vaccinated health workers at the 1st, 3rd, and 6th months following the second dose of the vaccination. The mean age of 235 health care workers who participated in the project was 39.51 ± 10.39 (min-max: 22–64). At the end of the 6th month, no antibodies were detected in 16.7% of Cohort-I participants, and anti-S-RDB IgG levels showed a decrease of 60% compared to the levels of the 3rd month. The antibody concentrations of the 6th month were found to have increased by an average of 5.13 times compared to the 3rd-month levels in Cohort-II and 20.4 times in Cohort-III. The heterologous vaccination strategy "CoronaVac and BNT162b2 regimen" is able to induce a stronger humoral immune response and it will help remove inequalities in the developing world where CoronaVac was the initial prime. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the efficacy of different COVID-19 booster vaccines by measuring the serum antibody titer. SARS-CoV-2 anti-nucleocapsid protein antibody (N-Ab), anti-spike protein antibody (S-Ab), and neutralizing antibody (Neut.Ab) were measured before and 4–6 weeks after booster vaccinations in healthcare personnel with a previous vaccination within 3–6 months. Personnel who previously received two doses of ChAdOx1 vaccine or two doses of BNT162b2 vaccine received the BNT162b2 vaccine (AAP and PPP groups, respectively). Personnel who previously received two doses of mRNA-1273 received the same vaccine as a booster dose (MMM group). Of the 917 participants, the AAP, MMM, and PPP groups comprised 837 (91.3%), 27 (2.9%), and 53 (5.8%) participants, respectively. The pre-booster S-Ab and Neut.Ab titer were significantly lower in the AAP group. After the booster vaccination, all participants were positive for S-Ab and Neut.Ab; furthermore, the S-Ab and Neut.Ab titer significantly increased in all three groups, although the post-booster S-Ab was lower in the AAP group than in the other groups. The post-booster Neut.Ab titer showed no significant difference among the groups. Our study’s results suggest that booster vaccination, after two prior vaccinations, shows a significant effect regardless of the type of vaccine administered.

To determine the factors associated with not receiving the booster dose for COVID-19 in Peru, a cross-sectional study by secondary analysis of a University of Maryland and Facebook survey database assessing the global impact of COVID-19 was conducted. Data of Peruvian users of this social network over 18 years of age who answered the survey between 13 February 2022 and 14 April 2022 were analyzed. We evaluated the association between sociodemographic characteristics, comorbidities, and history of COVID-19 with having received a booster dose for COVID-19. Crude (cPR) and adjusted (aPR) prevalence ratios with their respective 95% confidence intervals (95%CI) were calculated. A sample of 20,814 adults, 21.5% of whom reported not receiving the booster dose, was analyzed. People under 75 years of age had a higher prevalence of not having received the booster dose. Likewise, having a university education (aPR = 1.03; 95%CI: 1.02–1.05), secondary, or pre-university education (aPR = 1.07; 95%CI: 1.05–1.09), or having a primary level or less (aPR = 1.11; 95%CI: 1.05–1.18), were associated with a higher prevalence of not receiving the booster, compared to individuals with a postgraduate education. Being employed (aPR = 1.01; 95%CI: 1.00–1.02), having had COVID-19 (aPR = 1.03; 95%CI: 1.01–1.04) and living in a town (aPR = 1.05; 95%CI: 1.02–1.07) or in a rural area (aPR = 1.06; 95%CI: 1.03–1.10), compared to living in the city, had a similar association. On the contrary, the female gender was associated with a lower prevalence of not receiving the booster (aPR = 0.97; 95%CI: 0.96–0.99). Sociodemographic characteristics and a history of having had COVID-19 were associated with the probability of not having received the booster dose for COVID-19 in the Peruvian population.

This study aimed to evaluate the mixed and homogeneous application of the inactivated SARS-CoV-2 vaccine CoronaVac (CV) and the mRNA vaccine BNT162b2 (BNT). This prospective cohort study included 235 health care workers who had received two prime shots with CoronaVac. They were divided into three cohorts after the third month: Cohort-I (CV/CV); Cohort-II (CV/CV/CV); and Cohort-III (CV/CV/BNT). Anti-S-RBD-IgG and total anti-spike/anti-nucleocapsid-IgG antibody concentrations were examined in vaccinated health workers at the 1st, 3rd, and 6th months following the second dose of the vaccination. The mean age of 235 health care workers who participated in the project was 39.51 ± 10.39 (min-max: 22–64). At the end of the 6th month, no antibodies were detected in 16.7% of Cohort-I participants, and anti-S-RDB IgG levels showed a decrease of 60% compared to the levels of the 3rd month. The antibody concentrations of the 6th month were found to have increased by an average of 5.13 times compared to the 3rd-month levels in Cohort-II and 20.4 times in Cohort-III. The heterologous vaccination strategy “CoronaVac and BNT162b2 regimen” is able to induce a stronger humoral immune response and it will help remove inequalities in the developing world where CoronaVac was the initial prime.

Introduction: In the response to and prevention and control of the Novel coronavirus pneumonia, the COVID-19 vaccine does not provide lifelong immunity, and it is therefore important to increase the rate of booster shots of the COVID-19 vaccine. In the field of information health science, research has found that information frames have an impact in changing individual attitudes and health behaviors., Objective: This study focuses on the effects of different influencing factors on the public's willingness to receive the booster shots of the COVID-19 vaccine under two information frameworks., Methods: An online questionnaire was conducted to explore the effects of demographic characteristics, personal awareness, social relationships, risk disclosure, perceived booster vaccination protection rate, and duration of protection under the assumption of an information framework. T test and one-way analysis were used to testing the effect of variables., Results: (1) The persuasion effect under the gain frame is higher than that under the loss frame ( B  = 0.863 vs. B  = 0.746); (2) There was no significant difference in subjects' intention of booster vaccination in terms of gender, age, income, occupation, educational background and place of residence. Whether family members received booster vaccination was strongly correlated with their intention of vaccination under the loss framework ( p  = 0.017, M  = 4.63, SD = 0.664). (3) The higher the understanding of COVID-19, the higher the degree of compliance with the government's COVID-19 prevention and control measures, and the higher the willingness to strengthen vaccination; (4) Risk disclosure has a significant impact on people's willingness to receive COVID-19 booster shots ( M  = 2.48, under the loss framework; M  = 2.44, under the gain framework); (5) Vaccine protection rate and duration of protection have an impact on people's willingness to vaccinate. Increased willingness to vaccinate when the protection rate of booster vaccine approaches 90% ( M  = 4.76, under the loss framework; M  = 4.68, under the gain framework). When the vaccine protection period is 2 years, people are more willing to receive a booster vaccine; and the willingness to receive a booster shot is stronger under the loss framework ( M  = 4.60, SD = 0.721, p  = 0.879)., Conclusion: The impact of the information framework on COVID-19 vaccination intentions is different, and the disclosure of relevant health information should focus on the impact of the information framework and content on the public's behavior toward strengthening vaccination. Therefore, in the face of public health emergencies, public health departments, healthcare institutions, and other sectors can consider adopting the Gainful Information Framework tool to disseminate health information to achieve better persuasion and promote public health behavior change enhancing public health awareness, and promoting universal vaccination., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zhu, Gao, Hu, Hu and Wu.)

Background: Waning of COVID-19 vaccine efficacy/effectiveness (VE) has been observed across settings and epidemiological contexts. We conducted a systematic review of COVID-19 VE studies and performed a meta -regression analysis to improve understanding of determinants of waning., Methods: Systematic review of PubMed, medRxiv and the WHO-International Vaccine Access Center database summarizing VE studies on 31 December 2022. Studies were those presenting primary adult VE data from hybrid immunity or third/fourth mRNA COVID-19 monovalent vaccine doses [due to limited data with other vaccines] against Omicron, compared with unvaccinated individuals or individuals eligible for corresponding booster doses but who did not receive them. We used meta -regression models, adjusting for confounders, with weeks since vaccination as a restricted cubic spline, to estimate VE over time since vaccination., Results: We identified 55 eligible studies reporting 269 VE estimates. Most estimates (180/269; 67 %) described effectiveness of third dose vaccination; with 48 (18 %) and 41 (15 %) describing hybrid immunity and fourth dose effectiveness, respectively, mostly (200; 74 %) derived from test-negative design studies. Most estimates (176/269; 65 %) reported VE compared with unvaccinated comparison groups. Estimated VE against mild outcomes declined following third dose vaccination from 62 % (95 % CI: 58 % - 66 %) after 4 weeks to 48 % (41 % - 55 %) after 20 weeks. Fourth dose VE against mild COVID-19 declined from 48 % (41 % - 56 %) after 4 weeks to 47 % (19 % - 65 %) after 20 weeks. VE for severe outcomes was higher and declined in the three-dose group from 90 % (87 % - 92 %) after 4 weeks to 70 % (65 - 74 %) after 20 weeks., Conclusions: Time-since vaccination is an important determinant of booster dose VE, a finding which may support seasonal COVID-19 booster doses. Integration of VE and immunological parameters - and longer-term data including from other vaccine types - are needed to better-understand determinants of clinical protection., Competing Interests: JN used to work for, and holds shares in, Sanofi. BJC: has received honoraria from AstraZeneca, Fosun Pharma, GlaxoSmithKline, Haleon, Moderna, Novavax, Roche and Sanofi. The other authors declare no potential conflicts of interest.The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Joshua Nealon reports a relationship with Sanofi that includes: equity or stocks. Benjamin Cowling has received honoraria from AstraZeneca, Fosun Pharma, GlaxoSmithKline, Haleon, Moderna, Novavax, Roche and Sanofi., (© 2024 The Authors.)

Background: The long-term humoral immune response after vaccination varies between vaccines and is dependent on the accuracy of the antibody test. A better understanding of the vaccine immune response may help to define vaccination strategies against coronavirus disease 2019 (COVID-19)., Objective: To investigate the long-term immunological response to CoronaVac vaccine and determinants of breakthrough COVID-19 infection., Methods: A long-term, prospective cohort study involving vaccinated adult and elderly subjects was conducted to investigate the presence of anti-RBD-specific immunoglobulin (Ig)G, anti-nucleocapsid IgG and anti-spike trimeric protein IgG. Antibody level dynamics and risk factors associated with breakthrough COVID-19 infection were investigated., Results: In total, 3902 participants were included in this study. Vaccination with two doses of CoronaVac and a booster dose increased the levels of anti-RBD-specific IgG, anti-nucleocapsid IgG and anti-spike trimeric IgG significantly. In adults, anti-nucleocapsid IgG and anti-spike trimeric IgG levels decreased significantly 7 months after the second dose. In adults and the elderly, the levels of anti-spike trimeric IgG and anti-RBD IgG decreased significantly 4 and 6 months after the booster dose, respectively. Previous exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and anti-spike trimeric IgG titres was independently associated with a lower probability of post-vaccination infection., Conclusions: A significant increase in antibody levels was found after two doses of CoronaVac and a booster dose. Antibody titres declined significantly 7 months post-vaccination in participants who did not receive a booster dose. Higher levels of antibodies and previous SARS-CoV-2 infection were associated with protection against breakthrough COVID-19., Competing Interests: MCB, GJV, NNF, PMMG, GRM, BALF and RTC received research support from Instituto Butantan during the conduct of this study. SCSV, LBS, MAALSA, PEB, SK, HABG, JDF, MAL, PHMP and DTC are employees of Instituto Butantan., (© 2023 The Author(s).)

Background: Solid organ transplant recipients exhibit decreased antibody responses, mainly due to their weakened immune systems. However, data are limited on antibody responses after the primary series of coronavirus disease 2019 (COVID-19) vaccines among recipients of various solid organ transplant types. Thus, we compared the antibody responses after three COVID-19 vaccine doses between liver transplant (LT) and kidney transplant (KT) recipients., Methods: We prospectively enrolled solid organ transplant recipients who received three COVID-19 vaccine doses from June 2021 to February 2022 and measured S1-specific immunoglobulin G antibodies using an enzyme-linked immunosorbent assay., Results: Seventy-six LT and 17 KT recipients were included in the final analysis. KT recipients showed consistently lower antibody responses even after the third vaccine dose (86.2% vs. 52.9%, P=0.008) and lower antibody titers (median, 423.0 IU/mL [interquartile range, 99.6-2,057 IU/mL] vs. 19.7 IU/mL [interquartile range, 6.9-339.4 IU/mL]; P=0.006) than were observed in LT recipients. Mycophenolic acid was a significant risk factor for a seropositive antibody response after the third vaccine dose in the multivariable analysis (odds ratio, 0.06; 95% confidence interval, 0.00-0.39; P=0.02)., Conclusions: We found a weaker antibody response despite the completion of the primary series of COVID-19 vaccines in KT recipients than in LT recipients. Mycophenolic acid use in KT recipients might be the main contributor to this observation., Competing Interests: Conflict of Interest No potential conflict of interest relevant to this article was reported., (Copyright © 2023 The Korean Society for Transplantation.)

Booster doses have been described as effective in reducing hospitalizations and deaths from the new variants. However, its coverage is heterogeneous in Latin America and the Caribbean (LAC), one of the regions most affected by the pandemic. We aimed to assess the factors associated with not receiving a coronavirus disease 2019 (COVID-19) vaccine booster dose in adults from LAC. We analyzed a secondary database compiled by the University of Maryland and Facebook assessing the global impact of COVID-19. We included Facebook users over 18 years of age who resided in LAC and responded to the survey between February 13, 2022, and March 14, 2022. We evaluated sociodemographic characteristics, comorbidities, food, and economic insecurity, mental health, and vaccination-related practices. We calculated crude (cPR) and adjusted (aPR) prevalence ratios with their respective 95% confidence intervals (95%CI). The sample included 154,841 adults from 20 LAC countries. 33.7% (n = 46,459) reported not receiving the COVID-19 booster vaccine. Being under 75 years old, having a college, high school, pre-university, primary, or lower education, having no or 1 to 2 comorbidities, living in a town, having food insecurity, depressive symptoms, and having had COVID-19, were associated with a higher prevalence of not receiving the booster dose. In contrast, being female or non-binary and having anxiety symptoms were associated with a lower prevalence of not receiving the booster dose. Approximately three out of 10 adults surveyed in LAC reported not having received the booster vaccine. Authorities must design campaigns that promote receiving a booster dose considering the factors found. [ABSTRACT FROM AUTHOR]

Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have played a crucial role in mitigating the coronavirus disease 2019 (COVID-19) pandemic. However, few studies have addressed the optimal booster vaccine type in recipients of the primary series of BBIBP-CorV (an inactivated virus vaccine developed by Sinopharm). This study aimed to estimate the association between the heterologous or homologous COVID-19 vaccination and SARS-CoV-2 infection. The study enrolled healthcare personnel (HCP) who had completed two doses of BBIBP-CorV between November 2020 and September 2021. The associations between SARS-CoV-2 infection and boosters were measured using multivariable logistic regression, comparing the odds of a positive COVID-19 test result between the no booster group and booster groups (BNT162b2 {Pfizer-BioNTech COVID-19 vaccine} group and BBIBP-CorV group, respectively). A total of 495 HCP comprising 326 (65.9%) in the BNT162b2 group, 121 (24.4%) in the no booster group, and 48 (9.7%) in the BBIBP-CorV group enrolled. One hundred thirty-six cases (27.5%) tested positive for COVID-19. The odds ratios for testing positive after booster dose were 0.401 (95% CI: 0.187-0.860, p = 0.019) and 0.446 (95% CI: 0.170-1.167, p = 0.100) for BNT162b2 and BBIBP-CorV group, respectively. The BNT162b2 booster in HCP after a second dose of BBIBP-CorV, relative to no booster, and the BBIBP-CorV booster, was associated with protection against laboratory-confirmed COVID-19., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Park et al.)