Preliminary results from a late-stage study examining the efficacy of the Oxford-AstraZeneca 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 ages 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 provide information to the Food and Drug Administration needed to grant the AstraZeneca vaccine an emergency use authorization. This authorization would allow use of the vaccine by the general public to combat the coronavirus pandemic.
AstraZeneca's vaccine can be stored, transported and handled at normal refrigerated conditions (2 to 8 degrees Celsius or 36 to 46 degrees Fahrenheit) for at least six months. The company said it can also be administered without the need for preparation within existing health care settings.
The United States already has Pfizer, Moderna and Johnson & Johnson COVID-19 vaccines distributed to the general public. But the Pfizer and Moderna vaccines must be stored at extremely cold temperatures, making shipping, storage and distribution difficult.
The Centers for Disease Control and Prevention reported that as of Sunday 156,734,555 total vaccine doses have been distributed in the United States. The agency reports 124,481,412 vaccine doses have been administered.
The AstraZeneca vaccine is already being used around the world to prevent COVID-19. In recent weeks, several European countries temporarily suspended the use of the vaccine following reports of blood clotting in at least 30 patients.
Most countries resumed using it, however, after the European Medicines Agency conducted an investigation and declared on Thursday that the AstraZeneca vaccine is safe and effective. The agency said the benefits of the vaccine far outweigh the potential risks.