Pfizer has agreed to make another 100 million doses of its coronavirus vaccine for the United States, doubling the nation’s supply. In a statement published Wednesday morning, the drug maker said all 200 million doses will delivered by the end of July 2021, which, as a double-dose vaccine, will allow for 100 million Americans to be immunized. Health and Human Services Secretary Alex Azar said: “This new federal purchase can give Americans even more confidence that we will have enough supply to vaccinate every American who wants it by June 2021.” Pfizer also announced that the U.S. government has an option to buy as many as an additional 400 million doses of vaccine for delivery after July.