Writing in the journal Heart, the researchers describe how the adenovirus-based Covid vaccines produced by Oxford-AstraZeneca and Janssen, and the mRNA-based vaccines from Pfizer and Moderna, were most protective against Covid-related heart failure and blood clots in the first month after contracting the virus.
In that period, the risk of heart failure was 55% lower, and the risks of blood clots in the veins and arteries were down 78% and 47% respectively, compared with rates in unvaccinated people.
While the protective effects of the vaccines waned over the longer term, those who received Covid shots remained at lower risk of Covid-related heart failure and blood clots than unvaccinated individuals for up to a year, the researchers found.