Pfizer’s chief executive Albert Bourla on Monday has said that the drugmaker has not yet signed an agreement with the United States over providing 100 million more coronavirus vaccine doses in 2021.Bourla told a news agency in an interview that Pfizer is still involved in negotiation with the U.S. on whether it will be able to deliver the vaccine in the second or third quarter of the year. “The U.S. government is asking (for) more. They have asked now for an additional 100 million doses from us,” Bourla said. He adds that these extra doses were wanted in the second quarter of 2021. “We can provide them the additional 100 million doses, but right now most of that we can provide in the third quarter.” Bourla said. “The U.S. government wants them in the second quarter so are working very collaboratively with them to make sure that we can find ways to produce more or allocate the doses in the second quarter,” Bourla told the news agency. US administered the First Covid 19 vaccine, President Trump tweets US to buy 200 million doses of Moderna, first set of 20M to be delivered in December US to vaccinate 20 million this December, Covid 19 vaccination