US observational study finds risk of developing cerebral venous thrombosis (CVST) is higher in people with Covid-19 than in vaccine recipients

Analysis of electronic health records estimates the absolute incidence of CVST in 2 weeks following Covid-19 diagnosis (39 per million people; 95% CI 25.2-60.2) was higher than incidence following receipt of Pfizer or Moderna vaccines (4.1 per million people; 95% CI 1.1-14.9).

SPS commentary:

Reviews into reports of CVST in recipients of the AstraZeneca and Johnson & Johnson Covid-19 vaccines are ongoing. Although there are no data on the AstraZeneca vaccine from this study, as this has not used in the US, the authors note that their estimated risk of CVT following Covid-19 is higher than the latest estimate from the European Medicines Agency for the incidence associated with the AstraZeneca vaccine (5.0 per million people; 95% CI 4.3-5.8).

The authors discuss the various limitations associated with their study, and note that the rarity of CVST in all populations means that larger sample sizes are required to confirm the results, and complementary study designs are needed to aid interpretation. Nevertheless, the data highlight the risk of serious thrombotic events in COVID-19, and can help contextualize the risks and benefits of vaccination in this regard.

BBC Health News

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