The US Food and Drugs Administration (FDA) has said it will proceed with emergency use approval of the Pfizer-BioNTech Covid vaccine.
US Health Secretary Alex Azar said the vaccine should be authorised within a couple of days.
The Pfizer vaccine has already been approved for the public in the UK, Canada, Bahrain and Saudi Arabia.
On Wednesday the US recorded more than 3,000 deaths – the highest total in a single day anywhere in the world.
On Thursday, medical experts advising the FDA recommended the emergency use approval. A 23-member panel concluded the vaccine’s benefits outweighed its risks.
“Following yesterday’s positive advisory committee meeting outcome regarding the Pfizer-BioNTech Covid-19 vaccine, the US Food and Drug Administration has informed the sponsor that it will rapidly work toward finalisation and issuance of an emergency use authorisation,” the FDA statement said.
“The agency has also notified the US Centers for Disease Control and Prevention and Operation Warp Speed [the federal government’s vaccine distribution programme], so they can execute their plans for timely vaccine distribution.”
Mr Azar said the US would work with Pfizer to get the vaccine shipped out, so that it could be administered to the most vulnerable people by Monday or Tuesday.
Operation Warp Speed says that vaccine deliveries will begin within 24 hours of approval.
Pfizer plans to have 6.4 million doses ready for the US in its first rollout round in late December. Because two shots are required per person, that is enough for three million people, out of a total US population of 330 million.
Federal officials at the Centers for Disease Control and Prevention (CDC) say the nation’s 21 million healthcare workers should be prioritised first, as well the three million elderly Americans living in long-term care homes.
But there is less consensus on how states should distribute it to other groups. The nation’s approximately 87 million essential workers are expected to be next in line for the jab, but it will be up to states to decide which industries to prioritise.
Officials say vaccinations for groups that are not at a high risk are expected to take place in the spring of 2021.
A second vaccine, developed by Moderna and the National Institutes of Health, is also seeking emergency approval in the US. Like the Pfizer vaccine it requires a second round of injections.