Biden: U.S. will buy and donate 500M more COVID-19 vaccine doses for the world

President Biden will announce Wednesday the U.S. is purchasing an additional 500 million doses of the Pfizer-BioNTech coronavirus vaccine to give to the rest of the world, bringing its total commitment to more than 1 billion shots.

Mr. Biden will also press other global leaders to “step up” and do more during a COVID-19 summit that he is hosting on the sidelines of the U.N. General Assembly, according to a senior administration official.

“For every one shot we have administered in this country to date, we are now donating three shots to other countries. One shot here...