On Wednesday, Pfizer and BioNTech announced having reached a deal with the U.S. government with an additional 100 million doses by July 31.
That's up from the initial 100 million doses ordered already.
The deal follows a similar extension of doses reached by the U.S. with Moderna for their vaccine.
Both vaccines require two doses to be administered.
The $2 billion deal calls for at least an additional 70 million doses to be provided to the U.S. by June 30.
The remaining 30 million doses needing to be delivered by July 31.
It also allows for the U.S. to obtain up to an additional 400 million doses in the future.
