High-Dose - Adjuvanted Influenza Vaccines Found Safe for Older Adults

A non-peer-reviewed study supported by the U.S. Food and Drug Administration (FDA) as part of the SafeRx Project, a joint initiative of the Centers for Medicare & Medicaid Services, published on January 17, 2024, did not observe clear, consistent evidence of increased stroke risk following high to dose or adjuvanted influenza vaccination across the three flu seasons 2016 to 2019.

The statistically significant associations identified in this study were not consistently observed across outcomes, risk windows, age subgroups, or seasons.

Furthermore, the clinical significance of any potential risk of stroke following influenza vaccination must be carefully considered, together with the significant benefits of receiving an annual flu shot.

While studies have shown that influenza infections increase the risk of stroke, this study only included vaccinated cases and did not account for the protective effect of vaccination against infections. Address correspondence to Yun Lu, MS, PhD, Silver Spring, MD 20993; email: [email protected].