COVID-19 Vaccine Research Articles

The Effects of Behaviorally Informed Messages on COVID-19 Vaccination Intentions and Behavior: Evidence from Randomized Survey Experiments in South Africa

With COVID-19 vaccination rates remaining below optimal levels, scalable interventions to shift vaccination intentions are needed. We embedded two randomized experiments in South Africa’s COVID-19 Vaccine Survey (CVACS) to investigate the potential to change vaccine intentions and behavior. In Experiment 1, 3510 unvaccinated South African adults were randomly assigned to a no-message control group, a social norm message, or a message highlighting that vaccines were free, available and easy to obtain. The free and easy message significantly increased vaccine intentions but did not increase other outcome measures. The social proof message was associated with an increase in self-reported vaccination status at follow-up (not significant at traditional statistical thresholds). In Experiment 2, 3608 unvaccinated South African adults were randomly assigned to a no-message control group, a message highlighting gaining greater freedoms, or a message highlighting being part of the solution to the pandemic. Neither value proposition message increased vaccination intentions. Light-touch and scalable messages informed by behavioral science and social marketing principles may increase vaccination intentions and uptake, However, more attention should be paid to understanding the behavioral barriers experienced by different population segments, and to tailoring and targeting messaging to those barriers and segments.

Global burden of vaccine-associated Guillain-Barré syndrome over 170 countries from 1967 to 2023.

Research on Guillain-Barré syndrome (GBS) as a neurological adverse effect of vaccines on a global scale is scarce, highlighting the need for further investigation to evaluate its long-term impact and associated risk factors comprehensively. Hence, this study aims to assess the global burden of vaccine-associated GBS and its associated vaccines. This study utilized data from VigiBase, the World Health Organization global database of adverse event reports of medicines and vaccines, encompassing the period from 1967 to 2023 (total reports, n = 131,255,418) to investigate vaccine-associated GBS. Reported odds ratios (ROR) and information components (IC) were analyzed to assess the association between 19 vaccines and the occurrence of vaccine-associated GBS over 170 countries. We identified 15,377 (8072 males [52.49%]) reports of vaccine-associated GBS among 22,616 reports of all drugs-cause GBS from 1978 to 2023. Cumulative reports of vaccine-associated GBS have been increasing steadily over time, with a notable surge observed since the commencement of COVID-19 vaccines administration in 2020. Most vaccines showed significant associations with GBS such as Ad5-vectored COVID-19 vaccines (ROR, 14.88; IC, 3.66), COVID-19 mRNA vaccines (ROR, 9.66; IC, 2.84), and inactivated whole-virus COVID-19 vaccines (ROR, 3,29; IC 1.69). Influenza vaccines showed the highest association (ROR, 77.91; IC 5.98). Regarding age-and sex-specific risks, the association remained similar regardless of sex, with an increased association observed with advancing age. The mean time to onset was 5.5 days. Amid the COVID-19 pandemic, the reports of GBS surged in response to widespread COVID-19 vaccination. Nonetheless, COVID-19 vaccines exhibited the lowest association compared to other vaccines. Vigilance for at least one-week post-vaccination is crucial, particularly for older adults. Further research is warranted to elucidate the underlying mechanisms linking vaccines and GBS.

Myocarditis Associated with COVID-19 Vaccination.

Myocarditis after the COVID-19 vaccine is one of the important adverse events following immunization, observed mainly after mRNA-based vaccines. Importantly, post-vaccination myocarditis was less common than myocarditis after SARS-CoV-2 infection, as it was scored at 19.7 per 1,000,000 doses and 2.76 per 1000 infections. Predominantly, its course was benign and, compared with the myocarditis after COVID-19 infection, significantly fewer patients developed heart failure or died among patients with post-vaccination myocarditis. The group at highest risk of myocarditis related to COVID-19 vaccination were young males who received a second dose of an mRNA vaccine. It was observed that, among mRNA vaccines, specifically mRNA-1273 was associated with a higher risk of myocarditis. The mechanism underlying myocarditis after COVID-19 vaccination is still under investigation and certain processes are being considered. Currently, some follow-up assessments of patients who developed vaccine-induced myocarditis are available and suggest a favorable prognosis. The aim of this review is to discuss the most recent data on myocarditis after COVID-19 vaccination considering its epidemiology, clinical presentation, diagnosis, management, relative risk of myocarditis compared with SARS-CoV-2 infection, potential underlying mechanism, and follow-up data of patients who developed post-vaccination myocarditis.

COVID-19 vaccine implementation at a syringe services program: experiences of frontline staff

BackgroundWhile people with substance use disorders, including people who inject drugs (PWID), experience increased risk for COVID-19 infection and adverse outcomes, COVID-19 vaccination rates among PWID are consistently lower than those observed in the general population. Offering COVID-19 vaccines at syringe services programs (SSPs) has been proposed as a critical strategy to increase vaccine uptake among this population. We explored the experiences of frontline staff at an SSP in Miami, Florida implementing onsite COVID-19 vaccines.MethodsBetween June and July 2022, we conducted in-depth semi-structured interviews with 17 staff members of an SSP in Miami, Florida. Data collection and codebook thematic analysis of transcribed interviews were guided by the Consolidated Framework for Implementation Research (CFIR).ResultsFacilitators and barriers of COVID-19 vaccine implementation at the SSP aligned with all major CFIR domains. Key facilitators included the SSP’s established partnership with the local health department for vaccine distribution, its existing funding sources which could be leveraged for vaccine-related expenses, consensus among staff about the need for new strategies to increase vaccine uptake among PWID, and PWID’s trust in the SSP. Major—but largely modifiable—barriers included lack of participant compensation, limited internal collaboration and communication regarding the vaccine initiative beyond implementation leads and innovation deliverers due to competing priorities and segmented roles and responsibilities, and insufficient involvement of the most participant-facing staff (i.e., the SSP’s peer navigators and outreach workers).ConclusionsImplementing onsite COVID-19 vaccines was perceived as feasible and acceptable by frontline staff at the SSP, however contextual factors impeded optimal implementation. Multilevel strategies, such as participant compensation for vaccine completion and internal educational meetings with staff to improve vaccine implementation and reach, are required. As a trusted source of preventative services for PWID, SSPs are an underutilized venue for increasing vaccine uptake among this population, and findings from this study could inform the expansion of low-barrier vaccine services at SSPs nationwide.

The Global Burden of Absenteeism Related to COVID-19 Vaccine Side Effects Among Healthcare Workers: A Systematic Review and Meta-Analysis.

Background: A rise in absenteeism among healthcare workers (HCWs) was recorded during the COVID-19 pandemic, mostly attributed to SARS-CoV-2 infections. However, evidence suggests that COVID-19 vaccine-related side effects may have also contributed to absenteeism during this period. This study aimed to synthesize the evidence on the prevalence of absenteeism related to COVID-19 vaccine side effects among HCWs. Methods: The inclusion criteria for this review were original quantitative studies of any design, written in English, that addressed absenteeism related to the side effects of COVID-19 vaccines among HCWs. Four databases (PubMed, Scopus, Embase, and the Web of Science) were searched for eligible articles on 7 June 2024. The risk of bias was assessed using the Newcastle-Ottawa scale. Narrative synthesis and a meta-analysis were used to synthesize the evidence. Results: Nineteen observational studies with 96,786 participants were included. The pooled prevalence of absenteeism related to COVID-19 vaccine side effects was 17% (95% CI: 13-20%), while 83% (95% CI: 80-87%) of the vaccination events did not lead in any absenteeism. Study design, sex, vaccination dose, region, and vaccine type were identified as significant sources of heterogeneity. Conclusions: A non-negligible proportion of HCWs were absent from work after reporting side effects of the COVID-19 vaccine. Various demographic factors should be considered in future vaccination schedules for HCWs to potentially decrease the burden of absenteeism related to vaccine side effects. As most studies included self-reported questionnaire data, our results may be limited due to a recall bias. Other: The protocol of the study was preregistered in the PROSPERO database (CRD42024552517).

Understanding Factors Responsible for Delay and Non-Compliance in COVID-19 Vaccination at a Tertiary Care Hospital in Mumbai, India

Background: Despite extensive first-dose coverage, delays in second doses and late first doses prompted a study on vaccine hesitancy and non-compliance. Methods: In 2022, a cross-sectional survey was conducted at a Mumbai vaccination center, involving 504 individuals who had received either the first or second dose of the COVID-19 vaccine. The study, conducted from February to April 2022, included interviews using a pre-validated schedule to assess vaccine acceptance, refusal, socio-demographics, and reasons for hesitancy. Data analysis was performed using IBM SPSS Statistics software 23.0 to understand factors influencing vaccine delay and non-compliance. Result: The study interviewed 504 participants at a Mumbai vaccination center. Most were male (63.9%), aged 18-44 (80%), and skilled workers (22.6%). Of those surveyed, 64 had received only the first vaccine dose. The delay in receiving the second dose was 37.4% for BBV152 and 41% for ChAdOx1 nCoV-19. The primary reason for delay was lack of time (50.6%), followed by fear of the vaccine (14.8%). Reasons for getting vaccinated later included resolving constraints (40.5%) and compulsion (25.8%). Vaccine choice reasons varied significantly (p < 0.0005), but delay proportions were similar across vaccines (p = 0.531). Conclusion: Even after many efforts by the government, large numbers of people have not taken vaccine on time. One of the reasons, as seen in the study is a busy work schedule which has hindered timely vaccination in individuals. Making vaccine available at work place may address this issue to some extent, besides ownership of the program by the public.

The cost of COVID-19 vaccine delivery in Bangladesh

ABSTRACT COVID-19 vaccination has been instrumental in fighting the pandemic, but evidence on the actual costs associated with delivering these vaccines in resource-constrained settings has been limited. We estimated the cost of delivering COVID-19 vaccines in Bangladesh through five delivery strategies in 2021 and 2022, including Ministry of Health (MOH) hospitals, non-MOH government hospitals, outreach at Expanded Program on Immunization (EPI) centers, mass campaigns, and schools. This was a bottom-up costing study, estimating costs from a payer and beneficiary perspective. We also mapped the funding flows for COVID-19 vaccination activities and analyzed programmatic and financial challenges. The economic cost incurred by the health system to deliver COVID-19 vaccines was $1.05 per dose, excluding vaccine costs. This was made up of a financial cost of $0.29 per dose and an opportunity cost of $0.75 per dose. School-based delivery incurred the lowest financial cost of $0.27, while outreach at EPI centers incurred the highest at $0.44 per dose. The low financial cost per dose is attributed to the high daily volumes delivered at sampled sites, minimal additional resources provided to sites to implement the COVID-19 vaccination program, and a reliance on the existing workforce. Beneficiaries spent an average of $1.63 to receive a single dose of COVID-19 vaccination at fixed sites, with transport representing the largest cost driver ($0.75 per dose). The economic cost to receive one dose of the COVID-19 vaccine was $4.78. Findings can support the Government of Bangladesh to make efficient and equitable resource allocation decisions for vaccination programs.

A qualitative study of Chicago gay men and the Mpox outbreak of 2022 in the context of HIV/AIDS, PrEP, and COVID-19

During the 2022 mpox outbreak, our study conducted 30 interviews with a recruited sample of Chicago gay men (age 18+) during June-September to investigate their experiences of mpox, HIV/AIDS, and COVID-19. Participants were interviewed with a semi-structured guide about gay sexual identity and social experiences; HIV/AIDS, ART, and PrEP; and COVID-19 behaviors and vaccination. All 30 interview respondents had been fully vaccinated for COVID-19 and expressed minimal COVID-19 vaccine hesitancy. All the men living with HIV in our study were on ART with HIV well controlled. A majority of HIV- participants (70%) were on PrEP, with participants universally aware of PrEP benefits. Additionally, most participants had already received at least one shot of the Jynneos mpox vaccine, with many interviewees enduring long lines, sometimes at multiple locations, before vaccination in primarily gay social spaces. These Chicago gay men demonstrated widespread enthusiasm for mpox vaccination as a disease prevention strategy and most of them had already been vaccinated despite significant barriers. The enthusiasm of the participants in our study emerged within a medical landscape shaped by both COVID-19 vaccination and HIV/AIDS-related health interventions including ART and PrEP, which may have helped instill increased medical trust among this population. Our study suggests that out urban gay men may comprise a distinctive minority population with increased medical trust due to specific social, sexual, and historical experiences.

The acceptance of COVID-19 vaccines in Rwanda: a cross-sectional study

The first reported case of Coronavirus Disease 2019 (COVID-19) in Rwanda occurred on March 14 2020. By the end of July 2024, a total of 133,518 individuals had tested positive for the infection, resulting in 1,468 deaths and 132,039 had fully recovered. The success of COVID-19 elimination in Rwanda hinges on the public’s level of acceptance of the COVID-19 vaccination. Although COVID-19 is no longer a pandemic anymore, the World Health Organisation recommends countries vaccinate their populations to protect them from COVID-19 and its variants. Globally, COVID-19 has affected 704,753,890 people, caused 7,010,681 deaths and 675,619,811 have recovered. This study aimed to assess the acceptability of COVID-19 vaccines among adults aged 18 years and above in Rwanda. A cross-sectional study was conducted from January to March 2022 to determine the associations between COVID-19 vaccine acceptance (VA) with respondents’ characteristics, using logistic regression analysis. This study enrolled 2,126 respondents with a mean age of 31 years, the majority of whom were females (82.2%), 51.4% had completed primary education, and 78.7% were married. Most respondents recognized the importance of COVID-19 vaccination for both personal health and community well-being. The study found a high rate of COVID-19 vaccine acceptance, with 91.6% of respondents expressing VA and an overall VA rate of 98.2%. Having a relationship with the child(ren) was the only characteristic associated with COVID-19 vaccine acceptance (p; 3.2 × 10− 3, OR; 2.9, 95% C.I; 1.4–5.9). In conclusion, the study found a high rate of COVID-19 vaccine acceptance among adults in Rwanda, with COVID-19 associated with having a relationship with the child(ren). The study recommends the need for mass educational campaigns and awareness-raising efforts to understand of COVID-19 vaccines.

Impact of COVID-19 Vaccination on Menstrual Cycle, Quality of Life and Perception on Fertility: A Mixed Methods Study of Women in Delhi-NCR

The COVID-19 pandemic presented extraordinary challenges which led individuals to make global efforts to develop a vaccine that could help battle the spread of the infection. The COVID-19 vaccine came as a sigh of relief for the world, but whilst we assess the positives, we must consider looking into the potential impacts it has had on aspects of health, including female reproductive health. The current study aimed at assessing the potential impacts that COVID-19 vaccination had on menstrual cycles and the perception of women about fertility-related issues following the jab through a comprehensive mixed methods design. A structured survey, using the Menstrual Symptom Questionnaire (MSQ) and WHO Quality of life scale was carried out with a diverse sample (n=500) of women (18-40 years) in the Delhi-NCR region, collecting data on menstrual cycle changes post receiving the Vaccine. Additionally, semi-structured interviews were conducted with a subset of the participants (n=15) to understand the perceptions of women about fertility-related issues following the Vaccine. The study suggests that most of the participants reported facing menstrual concerns such as missed periods, menstrual irregularities, excessive menstrual bleeding and increased cramping on the first day of their period. Through semi-structured interviews, the themes that emerged were fear regarding conception, early menopause, infertility, mood changes, anxiety, fatigue, less pain tolerance and problems with menstrual flow. Alongside, many had low scores on the quality-of-life questionnaire which was understood better through semi-structured interviews. Cognitive distortions were observed among participants while they explained their perceptions of the whole scenario. The study seeks to address a critical topic and fill knowledge gaps to understand the possible health impacts the COVID-19 vaccine has on women’s reproductive health. The study would contribute to creating scientific evidence and valuable insights for the health industry to understand any potential side effects the vaccine could have.

Levels of high-sensitive troponin T and mid-regional pro-adrenomedullin after COVID-19 vaccination in vulnerable groups: monitoring cardiovascular safety of COVID-19 vaccination

BackgroundCOVID-19 vaccines are well tolerated and effective but may have adverse effects on the cardiovascular system. Vaccine-associated myocardial injury was analysed by measuring high-sensitive troponin T (hsTnT); mid-regional pro-adrenomedullin (MR-proADM) levels were evaluated to assess endothelial dysfunction.MethodsThis was a prospective study with a vulnerable population of healthcare workers (HCWs) and elderly patients (>70 years) who were vaccinated with either one dose of ChAdOx1 nCov-19 adenoviral vector vaccine (AZ) followed by one dose of the BNT162b2 messenger RNA vaccine (BNT), or with two doses of BNT (12th of January - 30th of November 2021). HsTnT and MR-proADM were measured in blood samples at three visits (V1: 1st immediately before vaccination; V2, 3: 3–4 weeks after 1st and 2nd vaccination). HsTnT of HCWs was compared to a healthy reference population.ResultsN = 162 volunteers were included (V1 = 161; V2, V3 = 162 each). N = 74 (45.7%) received AZ/BNT and n = 88 (54.3%) received BNT/BNT [elderly: n = 20 (12.3%), HCWs: n = 68 (42.0%)]. Median hsTnT levels were 4 ng/L, 5 ng/L and 4 ng/L (V1-V3) for AZ/BNT and at 5 ng/L, 6 ng/L and 6 ng/L (V1-V3) for BNT/BNT. Compared to the reference population (n = 300), hsTnT was significantly higher at all visits for both vaccination groups (p < 0.01), without differences between the AZ/BNT and BNT/BNT cohort. Median MR-proADM values were 0.43 nmol/L, 0.45 nmol/L, 0.44 nmol/L (V1-V3) in the AZ/BNT cohort and 0.49 nmol/L, 0.44 nmol/L, 0.47 nmol/L for BNT/BNT, respectively. Change of median hsTnT and MR-proADM between visits did not show significant increases. One HCW experienced a permanent and three a transient hsTnT increase ≥14 ng/L.ConclusionNo overall subtle, persistent cardiovascular involvement was observed after the 2nd COVID-19 vaccination. Elevated cardiovascular biomarkers in clinically asymptomatic individuals need further investigations.

Autoantibodies to protein S may explain rare cases of coagulopathy following COVID-19 vaccination.

While Coronavirus disease 2019 (COVID-19) vaccines have proven to be both effective and generally safe, rare but severe adverse events following immunization (AEFIs) are described. Autoantibodies to platelet factor-4 are associated with catastrophic thrombotic AEFIs, but comprehensive investigations of other autoantibodies are lacking. We aimed to detect and describe autoantibodies targeting coagulation-related proteins in a population-wide cohort (SWEDEGENE) including AEFIs attributed to COVID-19 vaccines in Sweden. Subjects were recruited from December 2020 to October 2022 and were stratified based on diagnosis and COVID-19 exposure. Screening was carried out in two phases, with a multiplex bead-based assay in the first subset (until September 2021) and with targeted assays for the second (until October 2022). Positivity was defined based on absolute, relative, and biological/technical thresholds. Patients with coagulation-related AEFIs were older and the Vaxzevria vaccine was overrepresented in this group. Two cases had antiphospholipid antibodies but none had PF4 antibodies. We identified six positives for protein S autoantibodies. Protein S concentrations were negatively correlated with autoantibody response in patients with immunoreactivity and functional analysis revealed low protein S activity in three subjects. Our population-wide analysis reveals cases with autoantibodies against protein S which possibly underlie coagulopathic AEFIs.

A behaviourally informed chatbot increases vaccination rates in Argentina more than a one-way reminder.

Maintaining COVID-19 vaccine demand was key to ending the global health emergency. To help do this, many governments used chatbots that provided personalized information guiding people on where, when and how to get vaccinated. We designed and tested a WhatsApp chatbot to understand whether two-way interactive messaging incorporating behaviourally informed functionalities could perform better than one-way message reminders. We ran a large-scale preregistered randomized controlled trial with 249,705 participants in Argentina, measuring vaccinations using Ministry of Health records. The behaviourally informed chatbot more than tripled COVID-19 vaccine uptake compared with the control group (a 1.6 percentage point increase (95% confidence interval, (1.36 pp, 1.77 pp)) and nearly doubled uptake compared with the one-way message reminder (a 1 percentage point increase (95% confidence interval, (0.83 pp, 1.17 pp)). Communications tools designed with behaviourally informed functionalities that simplify the vaccine user journey can increase vaccination more than traditional message reminders and may have applications to other health behaviours.

The risk of postherpetic neuralgia in COVID-19 vaccination-associated herpes zoster: A retrospective cohort study using TriNetX

BackgroundThe administration of the COVID-19 vaccine has been linked to the development of herpes zoster (HZ). However, studies examining the clinical outcomes in COVID-19 vaccination-associated and non-COVID-19 vaccination-associated HZ are lacking. ObjectiveTo investigate the risk of postherpetic neuralgia in COVID-19 vaccination associated HZ. MethodsA total of 7200 patients with COVID-19 vaccination-associated HZ and 7200 matched controls were enrolled from the US Collaborative Network in the TriNetX database. The main outcome of this study was the development of PHN.Patients were followed-up from 3 months after HZ until PHN diagnoses, withdrawal from the database, or October 8, 2024. ResultsWe observed that patients with COVID-19 vaccination-associated HZ had a significantly higher risk of developing PHN as compared to the control group, with hazard ratio of 1.69 (> 3 months), 1.80 (> 6 months), 1.86 (> 1 year), and 1.93 (>2 years), respectively. Additionally, the association remained significant in the stratified analysis, which included sex, age, malignancy status, and initial use of antiviral agents. ConclusionThis study showed that COVID-19 vaccination-associated HZ demonstrated a significantly higher risk of developing PHN.

Tixagevimab–cilgavimab for preventing breakthrough COVID-19 in dialysis patients: a prospective study

Abstract Background The effectiveness of tixagevimab–cilgavimab as pre-exposure prophylaxis (PrEP) against breakthrough coronavirus disease 2019 (COVID-19) in dialysis patients remains uncertain due to limited data. Methods In this multicenter prospective study, we enrolled vaccinated dialysis patients and divided them into two groups: tixagevimab–cilgavimab group (received a 150 mg/150 mg intramuscular dose of tixagevimab–cilgavimab) and control group (age-matched patients not receiving tixagevimab–cilgavimab). The primary outcome was the breakthrough COVID-19 rate at six months, whereas secondary outcomes included COVID-19-related hospitalization, ICU admission, endotracheal intubation, and mortality. The safety of tixagevimab–cilgavimab was assessed. Results Two hundred participants were enrolled, with equal numbers in each group (n = 100 each). Baseline characteristics were comparable between groups, except for a higher number of COVID-19 vaccine doses in the tixagevimab–cilgavimab group (median [IQR]: 4 [3–5] vs. 3 [3, 4]; P = 0.01). At six months, the breakthrough COVID-19 rates were comparable between the tixagevimab–cilgavimab (17%) and control (15%) groups (P = 0.66). However, the median (IQR) time to diagnosis of breakthrough infections tended to be longer in the tixagevimab–cilgavimab group (4.49 [2.81–4.98] vs. 1.96 [1.65–2.91] months; P = 0.08). Tixagevimab–cilgavimab significantly reduced COVID-19-related hospitalization rates (5.9% vs. 40.0%; P = 0.02) among participants with breakthrough infections. All tixagevimab–cilgavimab-related adverse events were mild. Conclusion The use of tixagevimab–cilgavimab as PrEP in vaccinated dialysis patients during the Omicron surge did not prevent breakthrough infections but significantly reduced COVID-19-related hospitalizations. Further research should prioritize alternative strategies.

Safety and immunogenicity of a modified mRNA-lipid nanoparticle vaccine candidate against COVID-19: Results from a phase 1, dose-escalation study

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

Influencing factors of antibody response after 2 doses of inactivated COVID-19 vaccine among adults aged ≥18 years in Chongqing, China: A cross-sectional serological study.

The study aimed to explore the influencing factors after 2 doses of inactivated COVID-19 vaccines (Sinopharm/BBIBP-CorV) in the real world. We conducted a cross-sectional serological study involving 316 volunteers aged ≧ 18 years from 7 vaccination hospitals in the Yubei districts, Yuzhong districts, and Jiulongpo districts of Chongqing. Serum samples were obtained about 1 month after 2 dose vaccination, and Nabs were tested using the pseudovirus-based neutralizing assay. Chi-square or Fisher exact tests were used to analyze the seropositive rates, while the Kruskal-Wallis H or Mann-Whitney U tests were used to analyze differences in Nabs level among stratified groups. Logistic regression analyses were conducted to identify the influencing factors. The results showed that seropositive rates was 76.27% and the GMT was 26.13 (95% CI: 23.03-29.66) after 2 doses of COVID-19 inactivated vaccination. The risk of being seropositive in 18 to 29, 30 to 39, 40 to 49, 50 to 59, and 60 to 69 years were 12.808-fold, 8.041-fold, 7.818-fold, 6.275-fold, 1.429-fold compared with the people aged ≥ 70 years (P < .05), and the risk of being seropositive of intervals 15 to 21 and 22 to 28 days were 0.273-fold and 0.286-fold compared with >28 days (P < .05), respectively. In conclusion, age may be a risk factor for reduced antibody production, and longer vaccination intervals-may be a protective factor that increases antibody production. These findings contribute to informing future vaccination strategies.

"Hot phase" clinical presentation of biventricular arrhythmogenic cardiomyopathy: when the perfect electrical storm spontaneously stops.

An 18-year-old male presented with syncope during a training break. Post-syncope, he developed effort dyspnea, which he associated with the Pfizer-BioNTech COVID-19 vaccine received a week earlier. Electrocardiogram showed T inversion in V1-V3, III, and aVF, while 24-hour Holter monitoring revealed frequent ventricular premature beats. A transthoracic echocardiogram showed severe biventricular dilation and mild left ventricular (LV) dysfunction. Cardiac magnetic resonance (CMR) imaging confirmed these findings, showing moderate right ventricular (RV) systolic dysfunction with akinesia of the inferior and inferolateral walls. T2 hypersignal in the middle segment of the inferior inferior interventricular septum suggested myocardial edema. Extensive transmural late gadolinium enhancement was noted in the RV and LV walls. An implantable loop recorder was implanted. Three months later, the patient was admitted with palpitations, fever, and a positive SARS-CoV-2 test. Sustained ventricular tachycardia (VT) episodes were documented and managed with amiodarone and β-blockers. Follow-up CMR showed a slight improvement in LV ejection fraction and resolution of edema. A single-chamber implantable cardioverter-defibrillator (ICD) was implanted. Genetic testing for arrhythmogenic RV cardiomyopathy (ARVC) was negative, and family screening was normal. Two years later, pre-syncope episodes occurred, and ICD interrogation revealed nonsustained VT. The patient is awaiting VT ablation. This case highlights the diagnostic and therapeutic challenges of ARVC, particularly in differentiating it from myocarditis. The "hot-phase" presentation, vaccine association, and subsequent SARS-CoV-2 infection added complexity. CMR was crucial for diagnosis, and VT management required a combination of medical therapy and invasive procedures.

COVID-19 Vaccine-induced antibody response to BNT162b2 mRNA in frontline healthcare workers

The emergence of SARS-CoV-2, the virus causing COVID-19, has resulted in a pandemic that has disrupted all sectors of society. Less than a year after the sequencing of the virus’s genome, emergency use authorization for the BNT162b2 vaccine was requested. The aim of this study was to evaluate the response to the BNT162b2-mRNA COVID-19 vaccine in frontline workers from two hospitals in Colombia. Nasopharyngeal swabs were collected for the molecular detection of SARS-CoV-2 using real-time PCR, and blood samples were taken to assess seroconversion using qualitative and quantitative IgA, IgG, and IgM test kits. The study was conducted at a high-complexity healthcare institution in Bucaramanga, Colombia. 245 people were included in the first round and 129 in the second. SARS-CoV-2 molecular tests were conducted by RT-qPCR, and peripheral blood samples were collected to measure IgG, IgM, and IgA. The main outcome was to establish natural infection and the antibody response induced by the vaccine. The entire population was tested at two fixed times with RT-PCR tests and antibody level measurements approximately 4 and 8 months after receiving the second vaccine dose. 62 (25.3%) and 35 (14.3%) participants had a history of positive PCR in the first and second rounds, respectively. All positive cases showed elevated levels of all immunoglobulins, especially IgG. The average concentrations of IgA, IgM, and IgG at 90 days were 1149.5 U/mL (95% CI 828.2-1470.9); 320.3 U/mL (95% CI 218.4-422.3); and 9277.3 U/mL (95% CI 8989.2-9565.3). Frontline healthcare workers showed an adequate response to the BNT162b2 mRNA vaccine.

Impact of Comorbidities and Skin Diseases on Post-Vaccination Reactions: A Study on COVID-19 Vaccinations in Poland.

Background: The COVID-19 pandemic necessitated rapid and widespread vaccination efforts, which proved critical in reducing the severity and mortality of the virus. However, the interplay between vaccinations, pre-existing skin conditions, and other comorbidities still needs to be explored. This study investigated the occurrence and severity of adverse events following immunization (AEFIs) with COVID-19 vaccines in individuals with chronic skin diseases and comorbidities within a Central European cohort. Methods: An anonymous online survey was conducted between May 2022 and February 2023, targeting students and employees of universities in Wrocław, Poland. A total of 513 respondents were analyzed, focusing on AEFIs following the first, second, and third doses of COVID-19 vaccines and the effects of COVID-19 on conditions such as atopic dermatitis, psoriasis, vitiligo, acne vulgaris, rosacea, and various comorbidities. Results: COVID-19 vaccination effectively protected against severe disease across all doses. The analysis revealed no significant impact of either COVID-19 infection or vaccination on the course of selected skin diseases and comorbidities. The reporting of AEFIs to the Sanitary Inspection was notably low. The Moderna and Pfizer mRNA-based vaccines were associated with a higher reported number of AEFIs, particularly after the second and third doses, compared to AstraZeneca, which exhibited fewer adverse events after subsequent doses. Conclusions: COVID-19 vaccination is both safe and effective, even in patients with pre-existing skin conditions and comorbidities. Vaccine selection may benefit from considering individual health profiles, and better reporting of AEFIs is needed to enhance vaccine safety monitoring.