Pharmaceuticals and Drug Trials
The vaccine also appears to work against the South African variant, B.1.351.
The small study of 2,260 U.S. volunteers has not yet been published.
Results from a U.S. trial of the vaccine may have used "outdated information," U.S. federal health officials said.
The shot was found 100% effective at preventing severe COVID-19, in early findings to be submitted to the Food and Drug Administration.
The government regulator approved a third vaccine to battle the coronavirus pandemic in the U.S. — and it's the only one so far to require just one dose.
If approved as expected by the Food and Drug Administration, this would be the third coronavirus vaccine available in the U.S. and the only one to require just one dose.
The FDA's panel of experts will meet Friday to decide whether to approve the coronavirus shot.
More than 38 million people in the U.S. have now received at least one dose of the Pfizer vaccine or another made by Moderna.
A preliminary study found the vaccine may be 76% effective if a second shot is given three months later rather than within the shorter window initially proposed.
Moscow was criticized for rolling out the vaccine before final data had been released.