AstraZeneca Covid-19 Vaccine Is 70% Effective on Average, Early Data Show

November 23, 2020

(STAT News) – AstraZeneca said Monday that its coronavirus vaccine reduced the risk of symptomatic Covid-19 by an average of 70.4%, according to an interim analysis of large Phase 3 trials conducted in the United Kingdom and Brazil. The results, while positive, suggest the vaccine may be less effective than two others. Earlier this month, Moderna and the Pfizer and BioNTech consortium announced their messenger RNA, or mRNA, vaccines showed 95% efficacy against Covid-19 infections in their respective clinical trials.