Relative vaccine effectiveness of ChAdOx1/AZD1222 vaccines as booster dose via intradermal injection with a one-fifth dose compared with the intramuscular injection in the prevention of SAR-CoV-2 infections in Phuket - A Retrospective Cohort Study.

OBJECTIVES: This study assessed the real-world relative vaccine effectiveness of the ChAdOx1/AZD1222 vaccine given intradermally at one-fifth dose compared to the standard intramuscular injection, following the completion of two doses of CoronaVac, due to limited vaccine availability in Thailand during the Coronavirus disease 2019 (COVID-19) pandemic. METHOD: This retrospective cohort study used 138,264 records from Vachira Phuket Hospital, Phuket, Thailand. The records were divided into two groups: 49,387 recipients received one-fifth doses via intradermal injections, and 88,877 recipients received standard-dose intramuscular injections from September 14 to October 3, 2021, with follow-up until December 31, 2021. Relative vaccine effectiveness for the cohorts was estimated using Cox regression, adjusting for demographic and clinical risk factors. RESULTS: The adjusted hazard ratio between the intradermal and intramuscular groups was 0.88 (95% Confidence Interval 0.76-1.02, p = 0.09), indicating a non-significant protective factor for the intradermal group. Further stratified analysis revealed no significant difference between the two groups. The 21 and 28-day post-vaccination periods minimized the possibility of confounding due to differences in the cohorts' timeframes. CONCLUSION: A booster dose of ChAdOx1/AZD1222 given intradermally at one-fifth dose did not show a significant difference compared to the standard intramuscular injection.

A health equity science approach to assessing drivers of COVID-19 vaccination coverage disparities over the course of the COVID-19 pandemic, United States, December 2020-December 2022.

INTRODUCTION: Health equity science examines underlying social determinants, or drivers, of health inequities by building an evidence base to guide action across programs, public health surveillance, policy, and communications efforts. A Social Vulnerability Index (SVI) was utilized during the COVID-19 response to identify areas where inequities exist and support communities with vaccination. We set out to assess COVID-19 vaccination coverage by two SVI themes, Racial and Ethnicity Minority Status and Housing Type and Transportation to examine disparities. METHODS: US county-level COVID-19 vaccine administration data among persons aged 5 years and older reported to the Centers for Disease Control and Prevention from December 14, 2020 to December 14, 2022, were analyzed. Counties were categorized 1) into tertiles (low, moderate, high) according to each SVI theme's level of vulnerability or 2) dichotomized by urban or rural classification. Primary series vaccination coverage per age group were assessed for SVI social factors by SVI theme tertiles or urbanicity. RESULTS: Older adults aged 65 years and older had the highest vaccination coverage across all vulnerability factors compared with children aged 5-17 years and adults aged 18-64 years. Overall, children and adults had higher vaccination coverage in counties of high vulnerability. Greater vaccination coverage differences were observed by urbanicity as rural counties had some of the lowest vaccination coverage for children and adults. CONCLUSION: COVID-19 vaccination efforts narrowed gaps in coverage for adults aged 65 years and older but larger vaccination coverage differences remained among younger populations. Moreover, greater disparities in coverage existed in rural counties. Health equity science approaches to analyses should extend beyond identifying differences by basic demographics such as race and ethnicity and include factors that provide context (housing, transportation, age, and geography) to assist with prioritization of vaccination efforts where true disparities in vaccination coverage exist.

Lessons for Future Vaccination Policies: COVID-19 Vaccination Intention in People with and without Chronic Diseases.

PURPOSE: This study compared COVID-19 vaccination intentions in those with and without chronic diseases (CDs and non-CDs) in South Korea. We hypothesized that the factors associated with COVID-19 vaccination intentions would differ between CDs and non-CDs in South Korea. METHOD: Using survey data collected through a Korean online panel in June 2021, we conducted a cross-sectional secondary data analysis. Of the 2,292 participants, 411 had at least one chronic disease. To construct a comparable dataset, we selected non-CDs via a 1:1 case-control matching for age and gender. We then utilized a multivariable binary logistic regression model to explore the factors contributing to COVID-19 vaccination intentions in CDs and non-CDs. RESULTS: All told, 75% of participants in both groups indicated that they intended to vaccinate against COVID-19. In both groups, those who mistrusted general vaccine benefits reported significantly lower COVID-19 vaccination intentions. Regarding factors associated with vaccination intentions, CDs identified anxiety regarding coronavirus and exposure to COVID-19 vaccination promotions at the community level, while non-CDs highlighted hesitancy regarding vaccines and confidence in government/health services. CONCLUSION: Improving vaccination acceptance will require the development and implementation of tailored approaches for CDs and non-CDs and efforts to minimize general vaccine mistrust.

Patient-reported outcomes of adverse events after COVID-19 vaccination in Nigeria: A mixed methods study.

BACKGROUND: Adverse events following immunization (AEFIs), especially if serious, may impact vaccine recipients' quality of life and financial well-being and fuel vaccine hesitancy. Nigeria rolled out COVID-19 vaccination in 2021 with little known about the impact of AEFIs on an individual's quality of life. No study in Africa has explored the health and financial impact of AEFIs. We explored patient-reported outcomes (PROs) of adverse events after COVID-19 vaccination and documented the lived experiences of those with serious AEFIs to understand the effect on their health, financial well-being, and attitude to future vaccinations. METHODS: We conducted a convergent mixed-methods study using the RAND 36-item health survey and in-depth interviews to collect PROs on vaccine recipients in Nigeria. Eight health scale scores and two summary composite scores were used to measure the health-related quality of life outcomes from the survey and inductive analysis was used to identify themes from the interview scripts. The results of both studies were integrated in a joint display to highlight areas of concordance. RESULTS: In total, 785 survey responses were analyzed (53% females, 68% aged 18-30 years). Responders reporting an AEFI were 58%, of whom 62% received the first dose only. Younger age and first vaccine dose (p < .001 respectively) were associated with experiencing an AEFI. Not reporting an AEFI was associated with better quality of life, measured as higher scores on all eight SF-36 Health scales and the physical and mental component summary scores. All six interviewees with serious AEFIs experienced physical, mental, and financial distress. Some expressed a strong negative attitude toward future COVID-19 vaccinations but not toward vaccines for routine immunization. CONCLUSION: AEFIs negatively impact the health and financial well-being of affected individuals and their attitude to future vaccinations, especially if serious. Understanding the impact of AEFIs on people is important and should inform future policies and interventions. The results of our study can inform policy and planning for future mass vaccination campaigns in LMICs.

Impact of recruitment strategies on individual participation practices in the Canadian National Vaccine Safety Network: prospective cohort study.

Background: The Canadian National Vaccine Safety (CANVAS) network conducted a multi-center, prospective vaccine safety study to collect safety data after dose 1 and 2 of COVID-19 vaccines and follow up safety information 7 months after dose 1. Objective: This study aimed to describe and evaluate the recruitment methods used by CANVAS and the retention of participants by each modality. Methods: CANVAS deployed a multi-pronged recruitment approach to reach a larger sample, without in-person recruitment. Three primary recruitment strategies were used: passive recruitment, technology-assisted electronic invitation through the vaccine booking system (auto-invitation), or auto-registration through the vaccine registries (auto-enrollment). Results: Between December 2020 and April 2022, approximately 1.3 million vaccinated adults either self-enrolled or were auto-enrolled in CANVAS, representing about 5% of the vaccinated adult Canadian population. Approximately 1 million participants were auto-enrolled, 300,000 were recruited by auto-invitation, and 5,000 via passive recruitment. Overall survey completion rates for dose 1, dose 2 and the 7-month follow-up surveys were 51.7% (681,198 of 1,318,838), 54.3% (369,552 of 681,198), and 66.4% (452,076 of 681,198), respectively. Completion rates were lower among auto-enrolled participants compared to passively recruited or auto-invited participants who self-enrolled. However, auto-enrolled samples were much larger, which offset the lower completion rates. Conclusion: Our data suggest that auto-enrollment provided an opportunity to reach and retain a larger number of individuals in the study compared to other recruitment modalities.

Immunogenicity, clinical efficacy, and safety of the sinopharm (BBIBP-CorV) SARS-CoV-2 vaccine among people with multiple sclerosis receiving disease-modifying therapies: a prospective cohort study.

BACKGROUND: To investigate the safety (adverse events [AEs] and post-vaccination multiple sclerosis [MS] activity within 6 weeks), clinical efficacy (protection against coronavirus disease 2019 [COVID-19]), and vaccine-induced humoral immunogenicity (SARS-CoV-2 neutralizing antibody, anti-nucleocapsid IgG, and anti-spike IgG) of the Sinopharm (BBIBP-CorV) vaccine among people with MS (PwMS) receiving different disease-modifying therapies (DMTs). METHODS: This prospective cohort study was conducted between November 2021 and May 2022. PwMS were followed for six months after the 2nd dose of vaccination. Antibody responses were measured 2-16 weeks after the 2nd dose injection. Multivariate logistic regression was employed to assess the impact of each DMT on dichotomous antibody responses, adjusting for age, sex, MS phenotype, expanded disability status scale, disease duration, and vaccination-antibody titration interval. RESULTS: Among the 261 screened PwMS, 209 (aged 38.23 ± 9.73 years, female: 70.8%; relapsing-remitting MS: 80.4%) were included. The frequencies of experiencing non-serious AEs and post-vaccination MS activity were 66.0% and 4.8%, respectively. Breakthrough COVID-19 infection was observed in 14.8% of the PwMS. A subcohort of 125 PwMS was assessed for antibody responses. Positive neutralizing antibodies, anti-nucleocapsid IgG, and anti-spike IgG were detected in 36.8%, 35.2%, and 52.0% of the PwMS, respectively. Multivariate regression indicated a 96% (OR: 0.04 [95% CI: 0.00, 0.51], P = 0.013), 93% (OR: 0.07 [0.01, 0.64], P = 0.019), and 89% (OR: 0.11 [0.01, 0.96], P = 0.045) reduced odds of positive neutralizing antibody, anti-nucleocapsid IgG, and anti-spike IgG, respectively, among fingolimod-receivers. Additionally, anti-CD20s-receivers had 88% (OR: 0.12 [0.02, 0.85], P = 0.034) lower odds of being positive for anti-nucleocapsid IgG. CONCLUSIONS: BBIBP-CorV appeared to be well tolerated in PwMS, with promising clinical efficacy. However, a suboptimal humoral response was observed in PwMS receiving fingolimod and anti-CD20s. Future research should investigate the relationship between humoral responses and the frequency and severity of COVID-19 infection across various DMTs.

4th booster-dose SARS-CoV-2 heterologous and homologous vaccination in rheumatological patients.

Objective: to evaluate the immune response to the SARS-CoV-2 vaccines in adults with immune-mediated rheumatic diseases (IMRDs) in comparison to healthy individuals, observed 1-20 weeks following the fourth vaccine dose. Additionally, to evaluate the impact of immunosuppressive therapies, vaccination schedules, the time interval between vaccination and sample collection on the vaccine's immune response. Methods: We designed a longitudinal observational study conducted at the rheumatology department of Hospital de Copiapó. Neutralizing antibodies (Nabs) titers against the Wuhan and Omicron variant were analyzed between 1-20 weeks after administration of the fourth dose of the SARS-CoV-2 vaccine to 341 participants (218 IMRD patients and 123 healthy controls). 218 IMRD patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), systemic vasculitis (VS) and systemic scleroderma (SS) were analyzed. Results: Performing a comparison between the variants, Wuhan vs Omicron, we noticed that there were significant differences (p<0.05) in the level of the ID50, both for healthy controls and for patients with IMRDs. The humoral response of patients with IMRDs is significantly lower compared to healthy controls for the Omicron variant of SARS-CoV-2 (p = 0.0015). The humoral response of patients with IMRDs decreases significantly when the time interval between vaccination and sample collection is greater than 35 days. This difference was observed in the response, both for the Wuhan variant and for the Omicron variant. Conclusion: The IMRDs patients, the humoral response variation in the SARS-CoV-2 vaccine depends on doses and type of vaccine administered, the humoral response times and the treatment that these patients are receiving.

Creating a Culturally Safe Online Data Collection Instrument to Measure Vaccine Confidence Among Indigenous Youth: Indigenous Consensus Method.

BACKGROUND:  Participating in surveys can shape the perception of participants related to the study topic. Administering a vaccine hesitancy questionnaire can have negative impacts on participants' vaccine confidence. This is particularly true for online and cross-cultural data collection because culturally safe health education to correct misinformation is typically not provided after the administration of an electronic survey. OBJECTIVE:  To create a culturally safe, online, COVID-19 vaccine confidence survey for Indigenous youth designed to collect authentic, culturally relevant data of their vaccine experiences, with a low risk of contributing to further vaccine confusion among participants. METHODS:  Using the Aboriginal Telehealth Knowledge Circle consensus method, a team of academics, health care providers, policy makers, and community partners reviewed COVID-19 vaccine hesitancy surveys used in public health research, analyzed potential risks, and created a framework for electronic Indigenous vaccine confidence surveys as well as survey items. RESULTS:  The framework for safer online survey items is based on 2 principles, a first do-no-harm approach and applying a strengths-based lens. Relevant survey domains identified in the process include sociodemographic information, participants' connection to their community, preferred sources for health information, vaccination uptake among family members and peers, as well as personal attitudes toward vaccines. A total of 44 survey items were developed, including 5 open-ended items to improve the authenticity of the data and the analysis of the experiences of Indigenous youth. CONCLUSIONS:  Using an Indigenous consensus method, we have developed an online COVID-19 vaccine confidence survey with culturally relevant domains and reduced the risk of amplifying misinformation and negative impacts on vaccine confidence among Indigenous participants. Our approach can be adapted to other online survey development in collaboration with Indigenous communities.

Lack of Evidence for Vaccine-Associated Enhanced Disease From COVID-19 Vaccines Among Adults in the Vaccine Safety Datalink.

PURPOSE: Vaccine-associated enhanced disease (VAED) is a theoretical concern with new vaccines, although trials of authorized vaccines against SARS-CoV-2 have not identified markers for VAED. The purpose of this study was to detect any signals for VAED among adults vaccinated against coronavirus disease 2019 (COVID-19). METHODS: In this cross-sectional study, we assessed COVID-19 severity as a proxy for VAED among 400 adults hospitalized for COVID-19 from March through October 2021 at eight US healthcare systems. Primary outcomes were admission to an intensive care unit (ICU) and severe illness (score ≥6 on the World Health Organization [WHO] Clinical Progression Scale). We compared the risk of outcomes among those who had completed a COVID-19 vaccine primary series versus those who were unvaccinated. We incorporated inverse propensity weights for vaccination status in a doubly robust regression model to estimate the causal average treatment effect. RESULTS: The causal risk ratio in vaccinated versus unvaccinated was 0.36 (95% confidence interval [CI], 0.15-0.94) for ICU admission and 0.46 (95% CI, 0.25-0.76) for severe illness. CONCLUSION: Among hospitalized patients, reduced disease severity in those vaccinated against COVID-19 supports the absence of VAED.

Vaccine pharmacovigilance in South Africa: successes and limitations of current approaches.

INTRODUCTION: Despite the public health success of vaccination, there is an ongoing need to build public confidence in vaccines and improve systems to monitor safety while maintaining data security and patient privacy. African countries face multiple challenges in establishing systems for vaccine pharmacovigilance as was demonstrated during COVID-19 mass vaccination. We provide a framework for the development of pharmacovigilance using the COVID-19 vaccination roll-out as an exemplar. AREAS COVERED: We describe the pre-COVID-19 vaccine pharmacovigilance systems in Southern Africa and propose improvements based on our experience of COVID-19 vaccine roll-out in South Africa where we implemented systems to evaluate real-world safety and effectiveness of COVID-19 vaccinations. By conducting a pubmed review of the literature on pharmacovigilance with a focus on Africa and from guidance emanating from the World Health Organisation (WHO), we evaluate challenges and opportunities to improve pharmacovigilance in our setting. EXPERT OPINION: There are ongoing efforts to improve pharmacovigilance on the African continent with improved coordination at a national level with the support of WHO, the national regulatory authorities, and national departments of health. COVID-19 vaccine roll-out provided an opportunity to improve pharmacovigilance by integrating national vaccine platforms with active and passive surveillance including hospital and death registries.

Incidence of narcolepsy symptoms after taking COVID-19 vaccines: a Jordanian cross-sectional study.

Purpose: Sleeping disorders were reported in many patients who took vaccines during previous pandemics. We aim to investigate the relationship between coronavirus disease 2019 (COVID-19) vaccines and the incidence of narcolepsy symptoms in the Jordanian population. Materials and Methods: We used a descriptive, cross-sectional, online self-administered survey conducted between December 2022 and May 2023. The survey targeted males and females above the age of 18 years who took any type of COVID-19 vaccine, had no chronic diseases, and had no sleep disorders prior to taking the vaccine. The survey was distributed via social media platforms. Results: A total of 873 participants were included in this study, consisting of 44.4% males and 55.6% females, with the majority being in the 18-29 age group. Most participants (79.8%) received two vaccine doses, with the Pfizer vaccine being the most common. Nearly half of the participants reported excessive daytime sleepiness. Sleep paralysis and hypnagogic hallucinations were reported by a notable proportion of participants, but no significant differences were found among the vaccine types. Sleep attacks and fragmented nighttime sleep were associated with the number of vaccine doses received, suggesting a possible influence of the dose count on these symptoms. The presence of excessive daytime sleepiness, sudden loss of muscle tone, sleep paralysis, and hypnagogic hallucinations showed no significant association with the number of doses taken. Conclusion: We hypothesize a possible link between COVID-19 vaccination and the emergence of narcolepsy symptoms in Jordanian individuals. Additional investigations and continuous monitoring to determine the extent of the risk and uncover potential mechanisms behind this connection should be performed.

Short- and long-term outcomes of cardiac adverse events following COVID-19 immunization managed in a Canadian pediatric center.

BACKGROUND: Numerous reports have described the clinical presentation of cardiac adverse events following immunization (AEFI) with COVID-19 vaccines but long-term outcome studies are limited, especially in the pediatric population. METHODS: This is a single center retrospective case series of pediatric patients with cardiac AEFI following the Pfizer/BioNTech mRNA COVID-19, diagnosed between May 2021 and May 2022, and managed following a standardized protocol. Follow up information is presented up to 12 months post diagnosis. The incidence rate of cardiac AEFI was estimated for Ottawa residents. RESULTS: All cases were male (N = 17) with an average age of 16 years (range = 12-17). The majority of cases occurred after the 2nd (12/17) or 3rd vaccine dose (4/17) and were manifested mostly as myopericarditis (15/17). Average interval between the 1st and 2nd vaccine (n = 12) doses was 38 days (21-69 days). All patients improved promptly on non-steroidal anti-inflammatory drugs without recurrence. Five patients reported negative impact on quality of life and mental health, including 2 cases that led to new vaccine hesitancy, not only to COVID-19 vaccine, but also to other routine vaccines. The rate of cardiac AEFI was estimated for residents of the city of Ottawa and found to be 12.01 cases (CI 90 5.98-21.68) per 100,000 doses following the 2nd dose and 16.56 cases (CI 90 5.66-37.90) per 100,000 doses following the 3rd dose for males aged 12 to 17 years. CONCLUSIONS: Twelve months following the AEFI, all patients clinically recovered from their myopericarditis, but some reported negative impact on quality of life and mental health, including new vaccine hesitancy. This highlights the importance for timely and systematic evaluation of AEFI and the need to provide support, follow up and vaccine counseling in individuals experiencing an AEFI.

Whole Exome Sequencing in Vaccine-Induced Thrombotic Thrombocytopenia (VITT).

Background: In February 2021, a few cases of unusual, severe thrombotic events associated with thrombocytopenia reported after vaccination with ChAdOx1 nCoV-19 (Vaxzevria) or with Johnson & Johnson's Janssen vaccine raise concern about safety. The vaccine-induced thrombotic thrombocytopenia (VITT) has been related to the presence of platelet-activating antibodies directed against platelet Factor 4. Objectives: We investigated VITT subject genetic background by a high-throughput whole exome sequencing (WES) approach in order to investigate VITT genetic predisposition. Methods: Six consecutive patients (females of Caucasian origin with a mean age of 64 years) were referred to the Atherothrombotic Diseases Center (Department of Experimental and Clinical Medicine, Azienda Ospedaliero-Universitaria Careggi, Florence) with a diagnosis of definite VITT underwent WES analysis. WES analysis was performed on the Illumina NextSeq500 platform. Results:WES analysis revealed a total of 140,563 genetic variants. Due to VITT's rare occurrence, we focused attention on rare variants. The global analysis of all high-quality rare variants did not reveal a significant enrichment of mutated genes in biological/functional pathways common to patients analyzed. Afterwards, we focused on rare variants in genes associated with blood coagulation and fibrinolysis, platelet activation and aggregation, integrin-mediated signaling pathway, and inflammation with particular attention to those involved in vascular damage, as well as autoimmune thrombocytopenia. According to ACMG criteria, 47/194 (24.2%) rare variants were classified as uncertain significance variants (VUS), whereas the remaining were likely benign/benign. Conclusion: WES analysis identifies rare variants possibly favoring the prothrombotic state triggered by the exposure to the vaccine. Functional studies and/or extensions to a larger number of patients might allow a more comprehensive definition of these molecular pathways.

Longitudinal Follow-Up Study on the Side Effects of COVID-19 Vaccines: A Telephonic Questionnaire Approach.

BACKGROUND: The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has prompted urgent efforts to develop and deploy effective vaccines. Covishield and Covaxin are two prominent COVID-19 vaccines authorized for emergency use; however, concerns regarding their safety persist. OBJECTIVE: This longitudinal follow-up study aimed to comprehensively assess and compare the demographic characteristics, frequencies, severities of reported side effects, and associations between vaccine type and demographic factors among individuals vaccinated with Covishield and Covaxin. METHODS: A telephonic questionnaire was used to collect data from individuals who attended COVID-19 vaccination programs between January 1, 2021, and January 1, 2022. Logistic regression analysis was performed to investigate the associations between vaccine type, demographic factors, and likelihood of experiencing side effects. RESULTS: Covaxin recipients exhibited a lower incidence of mild flu-like illness (16 cases) and post-vaccination infection (55 cases) than Covishield recipients (110 and 98 cases, respectively). However, Covaxin recipients reported more cases of soreness at the injection site (139 cases) than did Covishield recipients (172 cases). Logistic regression analysis revealed significantly higher odds of experiencing side effects among Covaxin recipients than among Covishield recipients (OR = 1.687, p < 0.001). Age was inversely associated with the likelihood of experiencing side effects (OR = 0.982, p < 0.001), while sex and ethnicity also exhibited significant associations. CONCLUSION: This study provides valuable insights into the safety profiles of the Covishield and Covaxin COVID-19 vaccines. These findings underscore the importance of ongoing surveillance and evaluation of vaccine safety and tolerability to inform public health policies and vaccination strategies.

Stability of Neutralizing Antibody of PastoCoAd Vaccine Candidates against a Variant of Concern of SARS-CoV-2 in Animal Models.

Background: Since the beginning of the SARS-CoV-2 pandemic, there have been mutations caused by new SARS-CoV-2 variants, such as Alpha, Beta, Gamma, Delta, and Omicron, recognized as the VOC worldwide. These variants can affect vaccine efficacy, disease control, and treatment effectiveness. The present study aimed to evaluate the levels of total and neutralizing antibodies produced by PastoCoAd vaccine candidates against the VOC strains at different time points. Methods: Two vaccine candidates were employed against SARS-CoV-2 using adenoviral vectors: prime only (a mixture of rAd5-S and rAd5 RBD-N) and heterologous prime-boost (rAd5-S/SOBERANA vaccine). The immunogenicity of these vaccine candidates was assessed in mouse, rabbit, and hamster models using ELISA assay and virus neutralization antibody test. Results: The immunogenicity results indicated a significant increase in both total and neutralizing antibodies titers in the groups receiving the vaccine candidates at various time points compared to the control group (p < 0.05). The results also showed that the PastoCoAd vaccine candidates Ad5 S & RBD-N and Ad5 S/SOBERANA could neutralize the VOC strains in the animal models. Conclusion: The ability of vaccine candidate to neutralize the VOC strains in animal models by generating neutralizing antibodies at different time points may be attributed to the use of the platform based on the Adenoviral vector, the N proteins in the Ad5 S & RBD-N vaccine candidate, and the SOBERANA Plus booster in the Ad5 S/SOBERANA vaccine candidate.

Comparison of Transient and Persistent Adverse Events After COVID-19 Vaccination: A Retrospective Analysis.

OBJECTIVE: Most reported adverse events following COVID-19 vaccination have been transient. However, persistent adverse events may occur with some frequency. This study aimed to analyze patient background characteristics and trends, with a focus on whether adverse events following COVID-19 vaccination were transient or persistent. METHODS: A retrospective study was performed at a single institution in Japan. PATIENTS: The study cohort included 47 patients who presented with symptoms after COVID-19 vaccination between May 2021 and September 2023. The patients were classified into two groups based on the duration of symptoms: transient group, less than four weeks; persistent group, greater than or equal to four weeks. Data on age, sex, body mass index, smoking history, underlying conditions, type of COVID-19 vaccination, number of doses, onset, symptoms, and treatments were collected retrospectively. RESULTS: The median age was 51.0 years and 74.5% were females, with a particularly high proportion of women in their 40s. The use of the bivalent omicron-containing booster vaccine (BA.1) was significantly more common in the persistent group than in the transient group (p = 0.0267). Onset in the transient group was more common after the first vaccination, whereas onset in the persistent group was more common after the second and subsequent vaccinations (p = 0.003). Regarding symptoms, pain was more frequent in the persistent group than in the transient group (60% vs. 13.6%; p = 0.001). CONCLUSIONS: This study investigated the presence of persistent symptoms, especially pain, after COVID-19 vaccination. Persistent symptoms were frequently reported after the second vaccination. It should be noted that the study does not negate the usefulness of COVID-19 vaccines.

Unstable angina pectoris in a young male after first dose of COVID-19 MRNA- vaccine.

Some side effects regarding COVID-19 vaccination have been reported. The most common reports of cardiovascular issues were myocarditis and pericarditis. Although inflammation is the most common cause in this matter, there were only a few reports about ischaemic cases related to COVID-19 vaccines. These reports also commonly included older men who received a second dose of mRNA vaccination. We present a 25-year-old man with chest pain mimicking a heart attack after receiving the first dose of the mRNA COVID-19 vaccine. There were no known preceding cardiovascular risk factors. Workups were done, and the diagnosis made was unstable angina pectoris. This may remind physicians to increase awareness of cardiovascular side effects in this vaccination era, as it may be encountered even in younger patients. The patient was seen at Dr. Soetomo General Academic Hospital, Surabaya, Indonesia, in August 2022.