Myocarditis and pericarditis associated with SARS-CoV-2 vaccines: A population-based descriptive cohort and a nested self-controlled risk interval study using electronic health care data from four European countries

Myocarditis associated with COVID-19 vaccination

Following the start of the COVID-19 vaccination campaign, the adverse events of myocarditis and pericarditis were linked mainly to mRNA COVID-19 vaccines by the regulatory authorities worldwide. COVID-19 vaccines have been administered to several million people and the risk of myocarditis post COVID-19 vaccination has been characterised in great detail. At the present time the research data available are scarce and there is still no clear understanding of the biological mechanism/s responsible for this disease. This manuscript provides a concise overview of the epidemiology of myocarditis and the most prominent mechanistic insights in the pathophysiology of the disease. Most importantly it underscores the needed next steps in the research agenda required to characterize the pathophysiology of this disease post-COVID-19 vaccination. Finally, it shares our perspectives and considerations for public health.

Importance of Examining Incidentality in Vaccine Safety Assessment

The author believes that the principles of statistical methods for vaccine safety can be divided into three categories: comparison of adverse event incidence rates between vaccinated and unvaccinated groups, analysis of incidentality in the vaccinated group, and a combination of both. The first category includes the cohort study; the second, the self-controlled risk interval design (SCRI); and the third, the self-controlled case series method. A single p-value alone should not determine a scientific conclusion, and analysis should be performed using multiple statistical methods with different principles. The author believes that using both the cohort study and the SCRI for analysis is the best method to assess vaccine safety. When the cohort study may not detect a significant difference owing to a low incidence rate of an adverse event in the vaccinated group or a high one in the unvaccinated group, the SCRI may detect it. Because vaccines must have a higher level of safety than the pharmaceuticals used for treatment, vaccine safety is advisable to be assessed using methods that can detect a significant difference even for any value of the incidence rate of an adverse event. The author believes that the analyses of COVID-19 vaccine safety have areas for improvement because the proportion of papers that used the cohort study and the SCRI was negligible.

The Role of the European Medicines Agency in the Safety Monitoring of COVID-19 Vaccines and Future Directions in Enhancing Vaccine Safety Globally

The European Union (EU) regulatory network was at the forefront of the safety monitoring of COVID-19 vaccines during the pandemic. An unprecedented number of case reports of suspected adverse reactions after vaccination called for huge efforts for the assessment of this safety information, to ensure that any possible risks were detected and managed as early as possible, while ruling out coincidental but temporally related adverse health outcomes. We describe the role of the European Medicines Agency alongside the EU regulatory network in the safety monitoring of the COVID-19 vaccines, and provide an insight into challenges, particularities and outcomes of the scientific assessment and regulatory decisions in the complex, dynamic international environment of the pandemic. We discuss the flexible procedural tools that were used to ensure an expedited scientific assessment of safety issues, and subsequent updates of the product information (i.e., labelling) when available evidence (e.g., spontaneous reports, findings from observational studies and/or scientific literature) suggested that causal association is at least a reasonable possibility. The safety monitoring was accompanied by enhanced transparency measures, proactive communication, and easy access to information, which played a key role in public reassurance. The pandemic has been a powerful booster for worldwide collaboration, exchange of information and work-sharing. The safety monitoring of COVID-19 vaccines continues, and the lessons learned will be applied in future safety reviews, as well as future health emergencies.

A comparison of four self-controlled study designs in an analysis of COVID-19 vaccines and myocarditis using five European databases

INTRODUCTION

The aim of this study was to assess the possible extent of bias due to violation of a core assumption (event-dependent exposures) when using self-controlled designs to analyse the association between COVID-19 vaccines and myocarditis.

METHODS

We used data from five European databases (Spain: BIFAP, FISABIO VID, and SIDIAP; Italy: ARS-Tuscany; England: CPRD Aurum) converted to the ConcePTION Common Data Model. Individuals who experienced both myocarditis and were vaccinated against COVID-19 between 1 September 2020 and the end of data availability in each country were included. We compared a self-controlled risk interval study (SCRI) using a pre-vaccination control window, an SCRI using a post-vaccination control window, a standard SCCS and an extension of the SCCS designed to handle violations of the assumption of event-dependent exposures.

RESULTS

We included 1,757 cases of myocarditis. For analyses of the first dose of the Pfizer vaccine, to which all databases contributed information, we found results consistent with a null effect in both of the SCRI and extended SCCS, but some indication of a harmful effect in a standard SCCS. For the second dose, we found evidence of a harmful association for all study designs, with relatively similar effect sizes (SCRI pre = 1.99, 1.40 - 2.82; SCRI post 2.13, 95 %CI - 1.43, 3.18; standard SCCS 1.79, 95 %CI 1.31 - 2.44, extended SCCS 1.52, 95 %CI = 1.08 - 2.15). Adjustment for calendar time did not change these conclusions. Findings using all designs were also consistent with a harmful effect following a second dose of the Moderna vaccine.

CONCLUSIONS

In the context of the known association between COVID-19 vaccines and myocarditis, we have demonstrated that two forms of SCRI and two forms of SCCS led to largely comparable results, possibly because of limited violation of the assumption of event-dependent exposures.

Frequency and timing of adverse reactions to COVID-19 vaccines; A multi-country cohort event monitoring study

INTRODUCTION

During the COVID-19 pandemic, EMA set-up a large-scale cohort event monitoring (CEM) system to estimate incidence rates of patient-reported adverse drug reactions (ADRs) of different COVID-19 vaccines across the participating countries. This study aims to give an up to date and in-depth analysis of the frequency of patient-reported ADRs after the 1st, 2nd, and booster vaccination, to identify potential predictors in developing ADRs and to describe time-to-onset (TTO) and time-to-recovery (TTR) of ADRs.

METHODS

A CEM study was rolled out in a period ranging from February 2021 to February 2023 across multiple European countries; The Netherlands, Belgium, France, the United Kingdom, Italy, Portugal, Romania, Slovakia and Spain. Analysis consisted of a descriptive analyses of frequencies of COVID-19 vaccine-related ADRs for 1st, 2nd and booster vaccination, analysis of potential predictors in developing ADRs with a generalized linear mixed-effects model, analysis of TTO and TTR of ADRs and a sensitivity analysis for loss to follow-up (L2FU).

RESULTS

A total of 29,837 participants completed at least the baseline and the first follow-up questionnaire for 1st and 2nd vaccination and 7,250 participants for the booster. The percentage of participants who reported at least one ADR is 74.32% (95%CI 73.82-74.81). Solicited ADRs, including injection site reactions, are very common across vaccination moments. Potential predictors for these reactions are the brand of vaccine used, the patient's age, sex and prior SARS-CoV-2 infection. The percentage of serious ADRs in the study is low for 1st and 2nd vaccination (0.24%, 95%CI 0.19--0.31) and booster (0.26%, 95%CI 0.15, 0.41). The TTO was 14 h (median) for dose 1 and slightly longer for dose 2 and booster dose. TTR is generally also within a few days. The effect of L2FU on estimations of frequency is limited.

CONCLUSION

Despite some limitations due to study design and study-roll out, CEM studies can allow prompt and almost real-time observations of the safety of medications directly from a patient-centered perspective, which can play a crucial role for regulatory bodies during an emergency setting such as the COVID-19 pandemic.

Assessing the temporal and cause-effect relationship between myocarditis and mRNA COVID-19 vaccines. A retrospective observational study

OBJECTIVE

In 2021, the US Centers for Disease Control and Prevention reported increased cases of myocarditis and pericarditis in the United States after mRNA COVID-19 vaccines. Our study aims to estimate the incidence of myocarditis in Apulia (Southern Italy) and the cause-effect relationship between COVID-19 mRNA vaccines and the risk of myocarditis.

METHODS

The Apulian regional archive of hospital discharge forms was used to define the cases of myocarditis in Apulia, considering data from 2017 to 2022. The overall vaccination status of patients was assessed via data collected from the Regional Immunization Database. The history of SARS-CoV-2 infection was extracted from the Italian Institute of Health platform.

RESULTS

Since 2017, 5687 cases of myocarditis have been recorded in Apulian subjects; the overall incidence described a decreasing trend, with a slight increase in 0-40 years-old subjects. From 2021 to 2022, 2,930,276 doses of COVID-19 mRNA vaccines were administered; a diagnosis of myocarditis after the second dose of the mRNA vaccine was reported for 894 (0.03%) of Apulian inhabitants, with an incidence rate of 17.9 × 1,000,000 persons-month. The multivariate analysis, adjusted for age, sex, underlying medical conditions, and diagnosis of COVID-19, showed that mRNA vaccination is a protective factor for myocarditis even in younger subjects (aOR = 0.4; 95% CI = 0.3-0.5).

CONCLUSION

A temporal association between an exposure and an outcome is not equivalent to a causal association. Our study underlines how an approach that considers the other potential causes of myocarditis (primarily COVID-19) and a causality assessment must be prioritized in the study of the topic.

Lessons learned from COVID-19, H1N1, and routine vaccine pharmacovigilance in the United States: a path to a more robust vaccine safety program

INTRODUCTION

Vaccine pharmacovigilance is an essential component of vaccine safety programs. Vaccine pharmacovigilance refers to detecting uncommon adverse events following immunization (AEFI), determining whether they are due to the vaccine or are only a coincidence, and, for those AEFI considered related to vaccination, characterizing them further. When AEFI are due to vaccination, it is important to characterize the attributable risk and ascertain the biological mechanism causing the adverse reaction to inform efforts to prevent or mitigate the risk. A robust post-authorization safety system is necessary for vaccine decision-making, clinical recommendations, vaccine compensation, and vaccine communication and confidence.

AREAS COVERED

This paper describes the key characteristics of vaccine pharmacovigilance programs, reviews US vaccine pharmacovigilance for routine vaccination programs, COVID-19, and H1N1, and makes recommendations for improving future vaccine safety systems.

EXPERT OPINION

The key characteristics of vaccine pharmacovigilance programs include passive surveillance, active surveillance, clinical investigation and special studies, and causality assessment. Recent examples illustrate the strengths of US pharmacovigilance systems, including systems for passive and active surveillance, as well as areas for improvement, including study of pathogenesis, consistent funding, and leadership. We make recommendations that would, if implemented, further strengthen the vaccine safety system for future routine and pandemic immunizations.

The role of real-world evidence for regulatory and public health decision-making for Accelerated Vaccine Deployment- a meeting report

The COVID-19 pandemic underscored the need for rapid evidence generation to inform public health decisions beyond the limitations of conventional clinical trials. This report summarises presentations and discussions from a conference on the role of Real-World Evidence (RWE) in expediting vaccine deployment. Attended by regulatory bodies, public health entities, and industry experts, the gathering was a collaborative exchange of experiences and recommendations for leveraging RWE for vaccine deployment. RWE proved instrumental in refining decision-making processes to optimise dosing regimens, enhance guidance on target populations, and steer vaccination strategies against emerging variants. Participants felt that RWE was successfully integrated into lifecycle management, encompassing boosters and safety considerations. However, challenges emerged, prompting a call for improvements in data quality, standardisation, and availability, acknowledging the variability and potential inaccuracies in data across diverse healthcare systems. Regulatory transparency should also be prioritised to foster public trust, and improved collaborations with governments are needed to streamline data collection and navigate data privacy regulations. Moreover, building and sustaining resources, expertise, and infrastructure in LMICs emerged as imperative for RWE-generating capabilities. Continued stakeholder collaboration and securing adequate funding emerged as vital pillars for advancing the use of RWE in shaping responsive and effective public health strategies.

Myocarditis and pericarditis risk with mRNA COVID-19 vaccination compared to unvaccinated individuals: A retrospective cohort study in a Spanish Tertiary Hospital

OBJECTIVE

This study compared the incidence of pericarditis and myocarditis in patients exposed to mRNA COVID-19 vaccines to the incidence in those who were not vaccinated, considering the incidence of these conditions resulting from COVID-19 infection.

METHODS

This was a retrospective cohort study of individuals assigned to health area of La Paz University Hospital in Spain. The exposure factor was vaccination with mRNA COVID-19 vaccines between December 27th, 2020 and January 9th, 2022 with a minimum follow-up of one month. The outcome was the incidence of pericarditis or myocarditis in these individuals.

RESULTS

The incidence of pericarditis and myocarditis in the total population exposed to at least one dose of mRNA COVID-19 vaccines was 5/100,000 (CI95%:3 to 8 per 100,000), compared to 70/100,000 (CI95%: 66 to 92 per 100,000) in those who were not vaccinated. In the adolescent population (aged 12-17), the incidence was 10/100,000 in vaccinated population (CI95%: 5 to 45 per 100,000) compared to 20/100,000 in unvaccinated (CI95%: 6 to 79 per 100,000). The incidence of pericarditis or myocarditis in patients with COVID-19 infection was 200/100,000 people (CI95%: 114 to 306 per 100,000). The most common cause of pericarditis and myocarditis in the cohort was idiopathic/infectious (74 cases). Cases of myocarditis attributed to COVID-19 infection were more severe and had higher mortality rates compared to cases with other causes.

CONCLUSION

The incidence of pericarditis and myocarditis in patients exposed to mRNA COVID-19 vaccines was lower than in those who were not vaccinated, especially in adults.The most common cause of pericarditis and myocarditis was idiopathic/infectious, but the most frequent cause in adolescent patients was mRNA COVID-19 vaccination. Cases of myocarditis due to COVID-19 infection were more severe and had greater mortality.

Cardiovascular, Neurological, and Immunological Adverse Events and the 23-Valent Pneumococcal Polysaccharide Vaccine

Importance

Despite widespread immunization with the 23-valent pneumococcal polysaccharide vaccine (PPSV23), safety concerns remain owing to a lack of statistical power and largely outdated evidence.

Objective

To evaluate the association between cardiovascular, neurological, and immunological adverse events and PPSV23 vaccination in older adults.

Design, Setting, and Participants

This population-based cohort study using a self-controlled risk interval design used a large linked database created by linking the Korea Immunization Registry Information System and the National Health Information Database (2018 to 2021). Participants included patients aged 65 years or older with a history of PPSV23 vaccination and incident cardiovascular, neurological, or immunological events during the risk and control intervals. Data were analyzed from November 2022 to April 2023.

Exposure

23-valent pneumococcal polysaccharide vaccine.

Main Outcomes and Measures

The occurrence of 1 among 6 cardiovascular events (myocardial infarction, atrial fibrillation, cardiomyopathy, heart failure, hypotension, and myocarditis or pericarditis), 2 neurological events (Bell palsy and Guillain-Barré syndrome), and 3 immunological events (sepsis, thrombocytopenia, and anaphylaxis) during the risk and control periods. The risk and control intervals were defined as 1 to 28 and 57 to 112 days after PPSV23 vaccination, respectively. Conditional Poisson regression was used to estimate the incidence rate ratio (IRR) with a 95% CI.

Results

Altogether, 4355 of the 1 802 739 individuals who received PPSV23 vaccination and experienced at least 1 outcome event were included (mean [SD] age, 72.4 [8.2] years; 2272 male participants [52.1%]). For cardiovascular events, there were no significant associations for myocardial infarction (IRR, 0.96; 95% CI, 0.81-1.15), heart failure (IRR, 0.85; 95% CI, 0.70-1.04), and stroke (IRR, 0.92; 95% CI, 0.84-1.02). Similarly, no increased risks were observed for neurological and immunological outcomes: Bell palsy (IRR, 0.95; 95% CI, 0.72-1.26), Guillain-Barré syndrome (IRR, 0.27; 95% CI, 0.06-1.17), sepsis (IRR, 0.99; 95% CI, 0.74-1.32), and thrombocytopenia (IRR, 1.18; 95% CI, 0.60-2.35).

Conclusions and Relevance

In this self-controlled risk interval study, there was no appreciable increase in risk for most cardiovascular, neurological, or immunological adverse events following PPSV23. The updated safety profile of PPSV23 provides supportive evidence for the establishment of immunization strategies for older adults.

A severe case of rhabdomyolysis after Moderna mRNA anti-COVID-19 vaccine with a literature review

The identification of rhabdomyolysis as a potential fatal adverse reaction to recent COVID-19 vaccines is essential. As the symptoms of rhabdomyolysis are not specific, the threshold to actively search for this complication should be low.