Several new studies on the Pfizer/BioNTech mRNA COVID-19 vaccine describe good effectiveness against the Delta (B1617.2) variant after a booster dose and high but waning protection against infection and severe illness 6 months after the second dose.
Other, much smaller, studies demonstrated the safety of third mRNA vaccine doses. And a new British study on waning two-dose effectiveness coincides with the recent decision by UK officials to recommend booster doses.
Tomorrow, Food and Drug Administration (FDA) advisors will discuss Pfizer’s application for the use of booster doses in the United States.
Infections 11 times lower after booster
Yesterday, the New England Journal of Medicine (NEJM) published three studies, the first of which—led by researchers from Weizmann Institute of Science in Rehovot, Israel—showed substantially reduced COVID-19 cases and severe illness after a booster dose. It involved more than 1.1 million Israelis 60 years and older who received a booster dose of the Pfizer vaccine from Jul 30 to Aug 31.