Vaccine Safety Monitoring System Research Articles

The Epidemiology of COVID-19 Vaccine-Induced Myocarditis.

In December 2019, the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to the COVID-19 pandemic, with millions of deaths worldwide. Vaccine breakthroughs in late 2020 resulted in the authorization of COVID-19 vaccines. While these vaccines have demonstrated efficacy, evidence from vaccine safety monitoring systems around the globe supported a causal association between COVID-19 vaccines, in particular those using mRNA technology, i.e., Moderna's mRNA-1273 and Pfizer-BioNTech's BNT162b2, and myocarditis. This paper aims to investigate the epidemiology of mRNA COVID-19 vaccine-induced myocarditis, including age, ethnicity, and gender associations with these vaccines. It also discusses the immunopathophysiological mechanisms of mRNA COVID-19 vaccine-associated myocarditis and outlines principles of diagnosis, clinical presentation, and management. A literature review was conducted using PubMed, Embase, and Queen Mary University of London Library Services databases. Search terms included "myocarditis," "coronavirus disease 2019," "SARS-CoV-2," "mRNA Covid-19 vaccines," "Covid vaccine-associated myocarditis," "epidemiology," "potential mechanisms," "myocarditis diagnosis," and "myocarditis management." While the definite mechanism of mRNA COVID-19 vaccine-associated myocarditis remains ambiguous, potential mechanisms include molecular mimicry of spike proteins and activation of the adaptive immune response with dysregulated cytokine expression. Male predominance in COVID-19 vaccine-induced myocarditis may be attributed to sex hormones, variations in inflammatory reactions, coagulation states based on gender, and female-specific protective factors. Moreover, an analysis of diagnostic and management strategies reveals a lack of consensus on acute patient presentation management. In contrast to viral infections that stand as the predominant etiological factor for myocarditis with more severe consequences, the mRNA COVID-19 vaccination elicits a mild and self-limiting manifestation of the condition. There is currently insufficient evidence to confirm the definite underlying mechanism of COVID-19 vaccine-associated myocarditis. Further research is needed to develop preventive and therapeutic solutions in this context.

Acute disseminated encephalomyelitis following the COVID-19 Vaccine Sinopharm in low- and middle-income country: a case report

Introduction and importance: Coronavirus disease 2019 (COVID-19) is a disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and various vaccines against it have been developed. Acute disseminated encephalomyelitis (ADEM) is a disease of the central nervous system that cause inflammation and demyelination and manifests as a multi-symptom acute neurological condition. Although infections are usually the cause of ADEM, vaccines may cause 5–10% of cases. Case presentation: A 40-year-old woman had received a second dose of the Sinopharm COVID-19 vaccine 4 months before her visit and experienced sudden gait imbalance and vertigo a day after her vaccination, which lasted for more than a month. On examination, no signs of skin bruising or bleeding were observed, and her vital signs were within the normal range. On neurological assessment, the patient had a Glasgow Coma Scale score of 14/15 (E4V5M5), had normal pupil size and light reaction, normal fundus, normal deep tendon reflexes and bilateral extensor plantar response. Meningeal symptoms were absent, and SARS-CoV-2 RNA tests using NAAT (Nucleic Acid Amplification Test) were negative. Development of central nervous system (CNS) manifestations during the recovery phase of fever, along with typical MRI findings; the diagnosis of para-infectious ADEM with COVID-19 vaccination was made. After the treatment with methylprednisolone sodium succinate injection, the patient showed improvement. Clinical discussion: ADEM associated with post-vaccinations is a rare condition. There has been growing evidence that shared epitopes between neuronal proteins and SARS-CoV-2 antigens may trigger autoimmune reactions against the CNS through molecular mimicry as its pathogenesis. Conclusion: We suggest the need for a strict vaccine safety monitoring system and post-vaccine monitoring and surveillance.

Barriers to optimal AEFI surveillance and documentation in Nigeria: Findings from a qualitative survey.

Effective spontaneous AEFI reporting is the first step to ensuring vaccine safety. Half of the global population lives in countries with weak vaccine safety monitoring systems, especially in the African, Eastern Mediterranean, and Western Pacific regions. Further, Immunisation services have been upscaled without commensurate effective AEFI surveillance systems. Hence, this study aims to comprehensively investigate the impediments to an effective AEFI surveillance system. Given the programmatic and regulatory implications, understanding these impediments would facilitate the development and implementation of policies and strategies to strengthen the AEFI surveillance system in Nigeria. A qualitative research design (using a grounded theory approach) was employed by conducting ten key informant interviews and two Focus Group Discussion sessions among the study population to identify the barriers impeding optimal AEFI surveillance and documentation in Nigeria. This study found that the AEFI surveillance system is in place in Nigeria. However, its functionality is sub-optimal, and the potential capacity is yet to be fully harnessed due to health systems and socio-ecological impediments. The identified impediments are human-resource-related issues- knowledge gaps; limited training; lack of designated officers for AEFI; excessive workload; poor supportive supervision and attitudinal issues; caregiver's factor; governance and leadership- moribund AEFI committee; lack of quality supervisory visit and oversight and weak implementation of AEFI policy guidance. Others include funding and logistics issues- no dedicated budget provision and weak referral mechanism; insecurity; socio-economic and infrastructural deficits- poverty, geographical barriers, limited ICT skills, and infrastructure; and poor feedback and weak community engagement by the health workers. Findings from this study provide empirical evidence and serve as an advocacy tool for vaccine pharmacovigilance strengthening in Nigeria. Addressing the impediments requires health system strengthening and a whole-of-the-society approach to improve vaccine safety surveillance, restore public confidence and promote vaccine demand, strengthen PHC services, and contribute to attaining UHC and SDGs.

Enlightening from optimizing post-authorization safety monitoring system of SARS-CoV-2 vaccines in major economies worldwide

Ongoing global pandemic of Coronavirus Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has promoted the unprecedented rapid development and large-scale rolling out of different platform-based COVID-19 vaccines worldwide. How to effectively respond to the expected scale increasing adverse events after vaccination campaign of COVID-19 vaccines is a common problem faced by the world. A lot of countries and regions around the world have arranged in advance at different levels, optimizing the original vaccine safety monitoring system from the perspectives of strengthening the foundation and capabilities, promoting internal and external cooperation, upgrading methods, as well as improving transparency and public communication, which has ensured the good and efficient operation of the system and can provide reference for the construction of relevant fields in China.

Thromboembolic Events, Anticoagulation, and COVID-19: Preemptive Treatments and Risks After Vaccination

Thromboembolic Events, Anticoagulation, and COVID-19: Preemptive Treatments and Risks After Vaccination

COVID-19 Vaccine Safety First Year Findings in Adolescents.

The Food and Drug Administration expanded Emergency Use Authorization for use of Pfizer-BioNTech (BNT-162b2) coronavirus disease 2019 vaccine to include people ages 12 years and older on May 10, 2021. We describe adverse events observed during the first full year of the US coronavirus disease 2019 vaccination program for adolescents ages 12 to 17 years. We conducted descriptive analyses using data from 2 complementary US vaccine safety monitoring systems: v-safe, a voluntary smartphone-based system that monitors reactions and health impacts, and the Vaccine Adverse Event Reporting System (VAERS), the national spontaneous reporting system. We reviewed reports and calculated adverse event reporting rates using vaccine administration data. Among 172 032 adolescents ages 12 to 17 years enrolled in v-safe, most reported reactions following BNT-162b2 were mild to moderate, most frequently reported on the day after vaccination, and more common after dose 2. VAERS received 20 240 adverse event reports; 91.5% were nonserious. Among adverse events of interest, we verified 40 cases of multisystem inflammation syndrome in children (1.2 cases per million vaccinations), 34 (85%) of which had evidence of prior severe acute respiratory syndrome coronavirus 2 infection; and 570 cases of myocarditis (17.7 cases per million vaccinations), most of whom (77%) reported symptom resolution at the time of report. During the first year BNT-162b2 was administered to adolescents ages 12 to 17 years, most reported adverse events were mild and appeared self-limited. Rates of myocarditis were lower than earlier reports. No new serious safety concerns were identified.

Acute disseminated encephalomyelitis following the COVID-19 vaccine Ad26.COV2.S, a case report

BackgroundThe severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has been leading to dramatic health, social and economic problems around the world. It was necessary to introduce worldwide vaccination program against SARS-CoV-2 virus. Vaccination of billions of people around the world leads to many questions about risk of vaccines and possible side effects. It is well known that acute disseminated encephalomyelitis (ADEM) is a rare, but possible complication of vaccines. Previously, cases of ADEM following various COVID-19 vaccines, including the vaccines from AstraZenica, Pfizer, Sputnik V, SinoVac, Moderna, Sinopharm, have been described. In this case report, we present the first documented case of ADEM following the COVID-19 vaccine Ad26.COV2.S from Johnson & Johnson.Case presentationWe present the case of a 31-year-old female with gradually progression of right-sided weakness and numbness during a three-week period. Four weeks prior to symptom onset, the patient received the single-dose SARS-CoV-2 vaccine Ad26.COV2.S. Neuroimaging revealed five large juxtacortical T2 FLAIR hyperintense lesions with incomplete contrast enhancement on post-contrast T1 images located supratentorial: one in the right cerebral hemisphere and four in left cerebral hemisphere. The patient was followed up for four months. Symptom debut, clinical picture and MRI were typical for ADEM and the patient completely recovered after high dose intravenous methylprednisolone treatment.ConclusionsThis is, to the best of our knowledge, the first case report of ADEM following the COVID-19 vaccine Ad26.COV2.S. This case illustrates, although ADEM is a rare complication following SARS-CoV-2 vaccines, the necessity of maintaining a vaccine safety monitoring system to identify patients at high risk from developing severe complications from the vaccines.

Safety of mRNA COVID-19 vaccines during pregnancy

Safety of mRNA COVID-19 vaccines during pregnancy

COVID-19 vaccines in pregnancy.

COVID-19 caused by SARS-CoV-2 coronavirus has been associated with severe illness in pregnant women. Furthermore, COVID-19 during pregnancy is associated with adverse fetal outcomes including preterm labor. Pregnant women were largely excluded from initial clinical trials investigating the safety and efficacy of COVID-19 vaccines; however, they have since been included as part of the routine roll-out of these vaccines. This narrative review synthesizes the evidence on the safety, immunogenicity, and effectiveness predominantly of the mRNA COVID-19 vaccines which have been most widely used in pregnant women.

Safety, Immunogenicity, Efficacy and Effectiveness of Inactivated Influenza Vaccines in Healthy Pregnant Women and Children Under 5 Years: An Evidence-Based Clinical Review.

Annual influenza vaccination is often recommended for pregnant women and young children to reduce the risk of severe influenza. However, most studies investigating the safety, immunogenicity, and efficacy or effectiveness of influenza vaccines are conducted in healthy adults. In this evidence-based clinical review, we provide an update on the safety profile, immunogenicity, and efficacy/effectiveness of inactivated influenza vaccines (IIVs) in healthy pregnant women and children <5 years old. Six electronic databases were searched until May 27, 2021. We identified 3,731 articles, of which 93 met the eligibility criteria and were included. The IIVs were generally well tolerated in pregnant women and young children, with low frequencies of adverse events following IIV administration; however, continuous vaccine safety monitoring systems are necessary to detect rare adverse events. IIVs generated good antibody responses, and the seroprotection rates after IIVs were moderate to high in pregnant women (range = 65%–96%) and young children (range = 50%–100%), varying between the different influenza types/subtypes and seasons. Studies show vaccine efficacy/effectiveness values of 50%–70% in pregnant women and 20%–90% in young children against lab-confirmed influenza, although the efficacy/effectiveness depended on the study design, host factors, vaccine type, manufacturing practices, and the antigenic match/mismatch between the influenza vaccine strains and the circulating strains. Current evidence suggests that the benefits of IIVs far outweigh the potential risks and that IIVs should be recommended for pregnant women and young children.

Vaccination reaction rate is unaltered by ambient temperature on the day

Minor reactions are often experienced following the human papillomavirus (HPV) vaccination and negative vaccination experiences may discourage individuals from seeking future vaccinations. Ambient temperature is suggested to be linked to reaction rates. Optimising immunisation programs requires understanding associations of temperature and reactions. To investigate a potential association between temperature and reactions, logistic regressions were performed on data obtained for a two-year period from a vaccine safety monitoring system for children (ages 10–15 years) who received the HPV vaccination (n = 20466) and from publicly available meteorological records in Australia. Reaction rate was 8.3% overall and higher with concomitant vaccination versus HPV alone (9.3% vs 7.8%, p=<0.001). Logistic regression found no relationship between reactions and maximal temperature on the day of vaccination (p = 0.581); controlling for concomitant vaccination, age and gender did not alter the temperature-reaction relationship (p = 0.851) but did identify concomitant vaccination as a significant predictor. Our results suggest immunisation programs must weigh the advantages of improved vaccination coverage resulting from concomitant vaccination against an increase in reaction rates and, importantly, can be safely administered across a range of temperatures.

Use of a new global indicator for vaccine safety surveillance and trends in adverse events following immunization reporting 2000–2015

Reporting of adverse events following immunization (AEFI) is a key component for functional vaccine safety monitoring system. The aim of our study is to document trends in the AEFI reporting ratio globally and across the six World Health Organization (WHO) regions. We describe the number of AEFI reports communicated each year through the World Health Organization/United Nations Children's Fund Joint Reporting Form on Immunization from 2000 to 2015. The AEFI reporting ratios (annual AEFI reports per 100,000 surviving infants) were calculated to identify WHO countries (n = 191 in 2000 and n = 194 by 2015) that met a minimal reporting ratio of 10, a target set by the Global Vaccine Action Plan for vaccine safety monitoring as a proxy measure for a functional AEFI reporting system. The number of countries reporting any AEFI fluctuated over time but with progress from 32 (17%) in 2000 to 124 (64%) in 2015. In 2015, the global average AEFI reporting ratio was 549 AEFI reports per 100,000 surviving infants. The number of countries with AEFI reporting ratios greater than 10 increased from 8 (4%) in 2000 to 81 (42%) in 2015. In 2015, 60% of countries in the WHO Region of the Americas reported at least 10 AEFI per 100,000 surviving infants, followed by 55% in European Region, 43% in Eastern Mediterranean Region, 33% in Western Pacific Region, 27% in South-East Asia Region and 21% in African Region. Overall, AEFI reporting has increased over the past sixteen years worldwide, but requires strengthening in a majority of low- and middle- income countries. The AEFI reporting ratio is useful for benchmarking and following trends over time; but does not provide information on the quality of the reporting system and does not guarantee capacity to detect and manage a vaccine safety problem at a national level. Additional efforts are required to ensure and improve data quality, AEFI reporting and surveillance of immunization safety in every country.

HPV Vaccination and Complex Regional Pain Syndrome: Lack of Evidence

HPV Vaccination and Complex Regional Pain Syndrome: Lack of Evidence

Vaccine safety monitoring systems in developing countries: an example of the Vietnam model.

Only few health intervention programs have been as successful as vaccination programs with respect to preventing morbidity and mortality in developing countries. However, the success of a vaccination program is threatened by rumors and misunderstanding about the risks of vaccines. It is short-sighted to plan the introduction of vaccines into developing countries unless effective vaccine safety monitoring systems are in place. Such systems that track adverse events following immunization (AEFI) is currently lacking in most developing countries. Therefore, any rumor may affect the entire vaccination program. Public health authorities should implement the safety monitoring system of vaccines, and disseminate safety issues in a proactive mode. Effective safety surveillance systems should allow for the conduct of both traditional and alternative epidemiologic studies through the use of prospective data sets. The vaccine safety data link implemented in Vietnam in mid-2002 indicates that it is feasible to establish a vaccine safety monitoring system for the communication of vaccine safety in developing countries. The data link provided the investigators an opportunity to evaluate AEFI related to measles vaccine. Implementing such vaccine safety monitoring system is useful in all developing countries. The system should be able to make objective and clear communication regarding safety issues of vaccines, and the data should be reported to the public on a regular basis for maintaining their confidence in vaccination programs.

Vaccine vigilance in Canada: Is it as robust as it could be?

Canada has been known to have one of the better vaccine safety surveillance capacities in the world, but in the early 2000s, it was noted there was still room for improvement. How has Canada done over the last decade and is there more to be done? Canada has done well. First, there has been significant progress made by the Vaccine Vigilance Working Group to enhance the passive vaccine safety monitoring system and address potential issues arising from the review of surveillance data and cases or clusters of concern. Second, there has been an increased investigative capacity for clusters of adverse events and other vaccine safety issues, including an assessment and referral system for individuals with adverse events following immunizations (AEFIs). Third, the use of the Brighton Collaboration definitions and other international standards has facilitated international collaboration and represents the best standard of practice. Despite all these improvements, however, there is more that could be done. The sensitivity of Canada's passive surveillance system still varies from one province and territory to another. The timeliness of the data exchange flow could improve. The AEFI Signal Response Protocol, which identifies the processes and required actions for timely management of any newly detected or emerging vaccine safety signals, is a critical piece of a robust vaccine safety system but it is still in the making. It is commendable that Canada has decided to expand its focus on evaluation research from influenza vaccines to vaccine-preventable diseases more broadly, with the establishment of the Canadian Immunization Research Network (CIRN). CIRN's newly developed Provincial Collaborative Network and the move toward record linkages is excellent. These new investments are welcome in light of the rich vaccine development pipeline, the increased pool of available vaccines, and the growing set of technologies for vaccines production, delivery, and safety monitoring. What would round this all out would be a stronger capacity to monitor the implementation of vaccination programs and vaccine coverage, and better documentation of the reduction of the disease burden attributable to vaccination programs. Canada's investment in vaccines for the health of all deserves no less.

Chart-Confirmed Guillain-Barre Syndrome After 2009 H1N1 Influenza Vaccination Among the Medicare Population, 2009-2010

Given the increased risk of Guillain-Barré Syndrome (GBS) found with the 1976 swine influenza vaccine, both active surveillance and end-of-season analyses on chart-confirmed cases were performed across multiple US vaccine safety monitoring systems, including the Medicare system, to evaluate the association of GBS after 2009 monovalent H1N1 influenza vaccination. Medically reviewed cases consisted of H1N1-vaccinated Medicare beneficiaries who were hospitalized for GBS. These cases were then classified by using Brighton Collaboration diagnostic criteria. Thirty-one persons had Brighton level 1, 2, or 3 GBS or Fisher Syndrome, with symptom onset 1-119 days after vaccination. Self-controlled risk interval analyses estimated GBS risk within the 6-week period immediately following H1N1 vaccination compared with a later control period, with additional adjustment for seasonality. Our results showed an elevated risk of GBS with 2009 monovalent H1N1 vaccination (incidence rate ratio = 2.41, 95% confidence interval: 1.14, 5.11; attributable risk = 2.84 per million doses administered, 95% confidence interval: 0.21, 5.48). This observed risk was slightly higher than that seen with previous seasonal influenza vaccines; however, additional results that used a stricter case definition (Brighton level 1 or 2) were not statistically significant, and our ability to account for preceding respiratory/gastrointestinal illness was limited. Furthermore, the observed risk was substantially lower than that seen with the 1976 swine influenza vaccine.

Current status and future directions of post-marketing vaccine safety monitoring with focus on USA and Europe

Vaccine safety research is a key component of public health programs. Regulatory agencies need to be able to make informed decisions. Public health authorities need to respond to vaccine concerns before they turn into large scale scares reducing vaccine uptake and derailing immunization programs. Several post-licensure vaccine safety monitoring systems have been established in the USA and Europe, and methods such as rapid cycle analysis have been developed for real-time detection and analysis of safety issues. Accurate and reliable vaccine product testing and monitoring requires high quality data of populations of 100 million and above depending on the frequency of the event, vaccine coverage, and the time pressure during which data need to be generated. This requires post-licensure safety studies utilizing large linked population based databases of exposure and outcomes. Harmonized methods for development and linkage of these databases across countries need to be further developed, validated and implemented. Concerted action between the US and Europe could move vaccine safety monitoring to today's level of requirements globally and should be pursued.

Surveillance for Adverse Events Following Receipt of Pandemic 2009 H1N1 Vaccine in the Post-Licensure Rapid Immunization Safety Monitoring (PRISM) System, 2009-2010

The Post-Licensure Rapid Immunization Safety Monitoring (PRISM) system is a cohort-based active surveillance network initiated by the US Department of Health and Human Services to supplement preexisting and other vaccine safety monitoring systems in tracking the safety of monovalent pandemic 2009 H1N1 influenza vaccine in the United States during 2009-2010. PRISM investigators conducted retrospective analysis to determine whether 2009 H1N1 vaccination was associated with increased risk of any of 14 prespecified outcomes. Five health insurance and associated companies with 38 million members and 9 state/city immunization registries contributed records on more than 2.6 million doses of 2009 H1N1 vaccine. Data on outcomes came from insurance claims. Complementary designs (self-controlled risk interval, case-centered, and current-vs.-historical comparison) were used to optimize control for confounding and statistical power. The self-controlled risk interval analysis of chart-confirmed Guillain-Barré syndrome found an elevated but not statistically significant incidence rate ratio following receipt of inactivated 2009 H1N1 vaccine (incidence rate ratio = 2.50, 95% confidence interval: 0.42, 15.0) and no cases following live attenuated 2009 H1N1 vaccine. The study did not control for infection prior to Guillain-Barré syndrome, which may have been a confounder. The risks of other health outcomes of interest were generally not significantly elevated after 2009 H1N1 vaccination.

Febrile seizures after 2010–2011 influenza vaccine in young children, United States: A vaccine safety signal from the vaccine adverse event reporting system

During the 2010-2011 influenza season, the Centers for Disease Control and Prevention and the Food and Drug Administration conducted enhanced vaccine safety monitoring for possible febrile seizures in all trivalent influenza vaccine (TIV) products in the United States using the Vaccine Adverse Event Reporting System (VAERS). We used Empirical Bayesian data mining techniques to assess disproportionate reporting after TIV and reviewed febrile seizure reports in children aged <5 years. On November 23, 2010, the combination of the coding term "febrile convulsion" and the Fluzone(®) TIV product exceeded a predetermined threshold in the VAERS database. By December 10, we confirmed 43 reports of febrile seizure following TIV in children aged 6-23 months. Clinical features of most reports were consistent with typical uncomplicated febrile seizures, and all children recovered. Further epidemiologic assessment of a possible association between TIV and febrile seizures was undertaken in a separate, population-based vaccine safety monitoring system.

The US Food and Drug Administration's Sentinel Initiative: Expanding the horizons of medical product safety

The US Food and Drug Administration's Sentinel Initiative: Expanding the horizons of medical product safety