AstraZeneca Vaccine Is Effective Against COVID-19, Phase III Study Says

Results from a Phase III trial show the Oxford AstraZeneca COVID-19 vaccine can be 79% effective at preventing symptoms of COVID-19.

Finnbarr Webster / Getty Images

Preliminary results from a study examining the efficacy of the Oxford-AstraZeneca coronavirus vaccine indicate it is significantly effective at preventing severe illness from COVID-19.

Results of the trial, which involved more than 32,000 volunteers, showed two doses of the vaccine administered four weeks apart had an efficacy of 79% at preventing symptoms of COVID-19. In participants aged 65 years and over, vaccine efficacy could be as high as 80%, AstraZeneca announced early Monday. It had an efficacy of 100% at preventing severe disease and hospitalization.

The results may mean the doses could soon be put into the arms of Americans. Data pulled from the study provides data to the Food and Drug Administration needed to grant the AstraZeneca vaccine an emergency use authorization. This approval would allow use of the vaccine by the general public to combat the coronavirus pandemic.