News release

From: American College of Physicians

2. No association found between mRNA vaccines and severe cardiovascular events
Adenoviral-based vaccines may increase risk for myocardial infarction and pulmonary embolism
Abstract: https://www.acpjournals.org/doi/10.7326/M22-0988
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A case-series study has found that adenoviral-based vaccines may be associated with increased risk for myocardial infarction (MI) and pulmonary embolism (PE). No association between mRNA vaccines and severe cardiovascular incidence was found in the short term. Myocarditis and pericarditis were not included in the study. Risk for The findings are published in Annals of Internal Medicine.

Incidence of hypertension and cardiovascular, thromboembolic, and hemorrhagic events have been reported for some recipients of both mRNA and adenoviral COVID-19 vaccines. Previous research has not found an association between mRNA vaccines and increased risk of cardiovascular events. However, some studies have reported increased risk for venous thromboembolism after receipt of adenoviral vaccines and arterial thromboembolism or hemorrhagic stroke after receipt of some mRNA vaccines.

Researchers from EPI-PHARE studied 46 million people aged 18 to 74 using data from the French National Health Data System, which provides comprehensive health care claims and hospitalization data for 99% of the French population, to assess short-term risk for severe cardiovascular events (excluding myocarditis and pericarditis) after COVID-19 vaccination. The authors identified persons who received up to two doses of a COVID-19 vaccine during a nonconsecutive three-week exposure period and experienced a subsequent cardiovascular event. Participants received the Pfizer–BioNTech, Moderna, Oxford–AstraZeneca, or Janssen (Johnson & Johnson) vaccine. The authors found that the relative incidence of MI was highest in persons who received a Janssen vaccine during the second week after their dose, with 43 percent of MI events being attributable to the vaccine. They also report that the relative incidence of MI and PE in the second week after receiving a first dose of the Oxford-AstraZeneca vaccine was 22 percent and 29 percent, respectively. There was no evidence of a positive association between the mRNA-based vaccines and acute MI, stroke, or PE in the 3 weeks after each of the first 2 doses. However, the authors note that vaccination, including with adenoviral-based vaccines, could decrease risk for a cardiovascular event by limiting the consequences of a potential SARS-CoV-2 infection.