The US Food and Drug Administration has authorised the Pfizer-BioNTech coronavirus vaccine for emergency use.
The agency said the authorisation was a “significant milestone” in the pandemic, which had taken more than 295,000 lives in the US.
The vaccine, which offers up to 95% protection against Covid-19, was deemed safe and effective by the FDA.
President Donald Trump said the first vaccinations will take place in less than 24 hours.
Before the announcement on Friday night, the FDA had come under intense pressure from the Trump administration to approve the vaccine’s use.
The Pfizer vaccine has already received regulatory approval in the UK, Canada, Bahrain and Saudi Arabia.
Like those countries, the US will give its first doses of the vaccine to the elderly, health workers and emergency crew.