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Study results suggest that COVID-19 vaccines are not associated with increased risk of sudden cardiac death in healthy young patients.
Publishing the findings of the study in PLoS Medicine on 19 March 2026, researchers found that exposure to any COVID-19 vaccination was not associated with increased odds of sudden death in healthy patients aged between 12–50 years.
There was also no significant difference between the first, second and third dose of the COVID-19 vaccine, the study results revealed.
While COVID-19 vaccines can cause “rare but serious adverse events, such as myocarditis and immune thrombotic thrombocytopenia”, the study authors said concerns have been expressed that the vaccines can cause death in healthy young adults, “despite a lack of strong evidence”.
They analysed data from more than 6 million residents of Ontario, Canada, aged 12–50 years, who experienced cardiac arrest between 1 April 2021 and 30 June 2023.
Patients with documented cardiovascular disease, mental health conditions or diseases that predispose a patient to adverse outcomes from COVID-19 were excluded from the study.
The researchers defined cases as those who died outside of hospital or who died within 24 hours of presentation to hospital.
Of the 4,963 cases who met the study’s definition of sudden death, the researchers found that COVID-19 vaccination was associated with a lower risk of sudden death, which was consistent across those vaccinated six weeks before death, those aged under 40 years, those who died in hospital or the emergency department and after exclusion of opioid-related deaths.
The study authors concluded that the study findings “do not support the hypothesis that COVID-19 vaccines increase the risk of sudden cardiac death in young healthy adults”.
However, they also noted that a limitation of the study was the inability to confirm the cause of death for patients who died outside of hospital.
Claire Anderson, president of the Royal Pharmaceutical Society, commented: “The findings from this study support existing evidence that COVID-19 vaccines do not increase the risk of sudden cardiac death in younger, healthy people.
“Importantly, this kind of real-world data helps address ongoing public concerns about vaccine safety. Pharmacists play a key role in supporting informed conversation with patients, helping to build confidence in vaccination, as well as supporting the delivery of vaccination programmes.”
Read more: ‘Calling the shots: the pharmacists combatting vaccine misinformation‘
