No elevated risk for stroke seen after COVID-19 bivalent vaccine receipt

For Medicare beneficiaries aged 65 years and older, there is no evidence of elevated stroke risk immediately after vaccination with either brand of the COVID-19 bivalent vaccine, according to a study published in the March 19 issue of the Journal of the American Medical Association.

Yun Lu, Ph.D., from the U.S. Food and Drug Administration in Silver Spring, Maryland, and colleagues examined stroke risk after administration of either brand of the COVID-19 bivalent vaccine, COVID-19 bivalent vaccine plus a high-dose or adjuvanted influenza vaccine on the same day (concomitant administration), and influenza vaccine.

The researchers observed no significant associations between either brand of the COVID-19 bivalent vaccine and stroke outcomes during the one- to 21-day or 22- to 42-day risk window versus the 43- to 90-day control window among the 11,001 beneficiaries who experienced stroke after receiving either brand of the COVID-19 bivalent vaccine.

There was a statistically significant association noted between vaccination and nonhemorrhagic stroke during the 22- to 42-day risk window for the BNT162b2 COVID-19 bivalent vaccine and between vaccination and transient ischemic attack during the one- to 21-day risk window for the mRNA-1273.222 COVID-19 bivalent vaccine among the 4,596 beneficiaries who experienced stroke after concomitant administration. A significant association was seen between vaccination and nonhemorrhagic stroke during the 22- to 42-day risk window among the 21,345 beneficiaries who experienced stroke after influenza vaccination.

"The study by Lu et al illustrates the value of a timely, well-designed analysis and has provided reassurance about the COVID-19 boosters," Kathryn M. Edwards, M.D., and Marie R. Griffin, M.D., M.P.H., from Vanderbilt University in Nashville, Tennessee, write in an accompanying editorial.