Internal Medicine PGY1 University of British Columbia, Canada
Background: Social media has fueled speculation that COVID-19 vaccines might cause sudden death in otherwise healthy young people. We examined the association between COVID-19 vaccination and sudden death in apparently healthy people aged 12 to 50 years.
METHODS AND RESULTS: We conducted a population-based case-control study using linked administrative healthcare data. We included all residents of Ontario, Canada who were alive on April 1, 2021. Exclusion criteria were age < 12 or >50 years, or history of cardiovascular disease, mental illness, or other diseases that predispose to adverse outcomes from COVID-19. We defined sudden death as out-of-hospital death or death within 24 hours of presentation to the hospital with a diagnosis of cardiac arrest. We included cases from April 1, 2021 to June 30, 2023. We matched each case to 5 controls who were alive on the index date (date of death for their matched case), matching on age, sex, and postal code of residence. We used conditional logistic regression to assess the association between COVID-19 vaccination and sudden death after adjusting for potential confounders.
Of 6,365,451 eligible people, we identified 4,963 cases (0.08%). Their median age was 36 years and 74.4% were male. In the primary analysis, any COVID-19 vaccination prior to the index date was associated with a markedly lower risk of sudden death (adjusted odds ratio [aOR] 0.57; 95% CI 0.53 to 0.61). The findings were consistent for COVID-19 vaccination within six weeks before index date (aOR 0.63; 95% CI 0.55 to 0.72), among people aged < 40 years (aOR 0.53; 95% CI, 0.48 to 0.58), those who died while in hospital or an emergency department (aOR 0.71; 95% CI 0.55 to 0.91), and after exclusion of opioid-related deaths (aOR 0.57; 95%CI 0.51 to 0.64). Individuals who received two doses of COVID-19 vaccination had a stronger negative association with death (aOR 0.53; 95%CI 0.49 to 0.57), while receipt of only one dose was less strongly associated with a lower risk of sudden death (aOR0.88; 95% CI 0.76 to 1.01).
Conclusion: In this population-based study, COVID-19 vaccination was associated with lower odds of sudden death in younger, apparently healthy individuals. These data refute the hypothesis that COVID-19 vaccines increase the risk of sudden cardiac death.
