New York City, 23 July 2021 (dpa-AFX/MIA) - Pfizer Inc. (PFE) and BioNTech SE (BNTX) announced Friday that the US 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 US government under its existing supply agreement to 500 million. On June 10, 2021, Pfizer and BioNTech shared plans to provide the US government with 500 million doses of the companies' Covid-19 vaccine for donation to the world's poorest nations. The companies expect to deliver 110 million of the additional doses by December 31, 2021, with the remaining 90 million doses to be delivered no later than April 30, 2022. The US government also has the option to acquire an updated version of the vaccine to address potential variants as well as new formulations of the vaccine, if available and authorized.