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

Abstract

Background: Estimates of the association between COVID-19 vaccines and myo-/pericarditis risk vary widely across studies due to scarcity of events, especially in age- and sex-stratified analyses.Methods: Population-based cohort study with nested self-controlled risk interval (SCRI) using healthcare data from five European databases. Individuals were followed from 01/01/2020 until end of data availability (31/12/2021 latest). Outcome was first myo-/pericarditis diagnosis. Exposures were first and second dose of Pfizer, AstraZeneca, Moderna, and Janssen COVID-19 vaccines. Baseline incidence rates (IRs), and vaccine- and dose-specific IRs and rate differences were calculated from the cohort The SCRI calculated calendar time-adjusted IR ratios (IRR), using a 60-day pre-vaccination control period and dose-specific 28-day risk windows. IRRs were pooled using random effects meta-analysis.Findings: Over 35 million individuals (49·2% women, median age 39–49 years) were included, of which 57·4% received at least one COVID-19 vaccine dose. Baseline incidence of myocarditis was low. Myocarditis IRRs were elevated after vaccination in those aged < 30 years, after both Pfizer vaccine doses (IRR = 3·3, 95%CI 1·2-9.4; 7·8, 95%CI 2·6-23·5, respectively) and Moderna vaccine dose 2 (IRR = 6·1, 95%CI 1·1-33·5). An effect of AstraZeneca vaccine dose 2 could not be excluded (IRR = 2·42, 95%CI 0·96-6·07). Pericarditis was not associated with vaccination.Interpretation: mRNA-based COVID-19 vaccines and potentially AstraZeneca are associated with increased myocarditis risk in younger individuals, although absolute incidence remains low. More data on children (≤ 11 years) are needed.

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

“…In the study of Bots et al-a populationbased descriptive cohort and a nested self-controlled risk interval study using 5 European databases that included over 35 million individuals-the authors concluded the myocarditis rates were elevated in individuals less than 30 years old after both doses of the Pfizer vaccine and the second dose of the Moderna vaccine. 28 In our case report, myocarditis was unlikely, as the patient did not have chest pain, and the electrocardiogram was normal.…”

“…In rhabdomyolysis cases, cardiac involvement must be considered, as many myocarditis and pericarditis have been reported. In the study of Bots et al—a population‐based descriptive cohort and a nested self‐controlled risk interval study using 5 European databases that included over 35 million individuals—the authors concluded the myocarditis rates were elevated in individuals less than 30 years old after both doses of the Pfizer vaccine and the second dose of the Moderna vaccine 28 …”

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

“…The risk interval was defined as days 1 to 28 after PPSV23 vaccination, while the control interval was defined as days 57 to 112 after PPSV23 vaccination, with day 0 defined as the day of PPSV23 vaccination. The adoption of a 28-day risk period aligns with previous studies investigating the cardiovascular, neurological, or immunological events associated with vaccination . We excluded outcomes that occurred on the day of vaccination to account for the possibility of reverse causation, unless stated otherwise.…”

A comparison of four self-controlled study designs in an analysis of COVID-19 vaccines and Myocarditis using Five European Databases

“…Our hypotheses regarding the extent of bias can be seen in Table 1when the assumption of event-dependent exposures is violated. (10), and have been described in greater detail in previous publications (11).…”

“…The core methods have been previously described (11). Briefly, individuals who experienced both the outcome of interest and were vaccinated between 1 September 2020 and the end of data availability (which varied in the different databases) were eligible for inclusion.…”