US health officials have signed a contract with pharmaceuticals giant Pfizer and biotech firm BioNtech to buy 100 million doses of their Covid-19 vaccine once it's approved for use, APA reports citing BBC.
Health Secretary Alex Azar said that production would start in December and that the country could acquire a further 500 million doses. The vaccine will be free to all US residents, although their insurance may be charged, said the US Department of Health and Human Services.
In clinical trials, Pfizer and BioNTech have been testing vaccines that require two injections, so a supply of 100m doses would likely vaccinate 50 million Americans.
In May, the US pledged $1.2bn (£940m) to secure 300 million doses of another AstraZeneca vaccine being developed by Oxford University.
Neither vaccine has yet been approved for use but both have produced positive data in clinical trials.