WASHINGTON (AP) — The White House says the U.S. will begin sharing its entire stock of AstraZeneca COVID-19 vaccines with the world once it clears federal safety reviews. As many as 60 million doses are expected to be available for export in the coming months. The move greatly expands on the Biden administration’s action last month to share about 4 million doses of the vaccine with Mexico and Canada. The AstraZeneca drug is widely in use around the world but has not yet been authorized by the U.S. Food and Drug Administration. The White House is increasingly assured about the supply of the three vaccines being administered in the U.S.