The bottles for the Pfizer BioNTech COVID-19 vaccine can be prepared prior to the opening of a mass vaccination site in Queens, New York City on February 24, 2021.

Seth Little | Pool | Reuters

Albert Bourla, CEO of Pfizer, said Tuesday that his company had ramped up production of its two-shot coronavirus vaccine and could ship a total of 300 million doses to the U.S. ahead of schedule.

Bourla said on Twitter that Pfizer can ship 10% more doses to the US by the end of May than previously agreed – up to 220 million out of 200 million.

The company will be able to ship the full $ 300 million to the US two weeks early, Bourla said.

“We’re in the fight against COVID-19 together,” he tweeted.

The announcement came when dozen of states temporarily stopped giving Johnson & Johnson’s single-dose Covid vaccine. The Food and Drug Administration advised them to do so on Tuesday after six women in the United States developed a rare bleeding disorder in which one woman was dead and another in critical condition.

Some states, like New York, said they would use Pfizer’s vaccine instead of the J&J shot for appointments that were already scheduled.

President Joe Biden set a goal last month to get enough Americans vaccinated in time for them to safely gather in small groups for July 4th. He also vowed that every adult in the US would have access to the vaccine by the end of May.

The Biden government announced in February that it had bought enough doses of vaccine from Pfizer and Moderna for each company to have 300 million shots by the end of July. The government’s total purchase from Pfizer was approximately $ 6 billion.

While the U.S. is vaccinating more people than ever before, it is also reporting about as many new Covid cases per day as it was during the surge last summer. The nation has had an average of 68,758 new infections in the past seven days, and cases tend to be higher in many states, according to Johns Hopkins University.

Just over 20% of the US population is fully vaccinated, according to Johns Hopkins. This is well below the 70% to 85% threshold that Biden’s best medical advisor, Dr. Anthony Fauci, is needed for the country to achieve herd immunity and suppress the pandemic.