Pfizer Inc. (NYSE: PFE) and BioNTech SE (Nasdaq: BNTX) announced that the U.S. government has purchased an additional 200 million doses of the Pfizer-BioNTech COVID-19 Vaccine. These doses are expected to be delivered from October 2021 through April 2022. This brings the total number of doses to be supplied by the companies to the U.S. government under its existing supply agreement to 500 million.