The US Food and Drug Administration has authorised the use of Pfizer’s COVID-19 vaccine, with the first inoculations expected within days, marking a turning point in the United States where the pandemic has killed more than 292,000 people.

The FDA granted an emergency use authorisation for the vaccine, developed with German partner BioNTech, which was shown to be 95 per cent effective in preventing the disease in a late-stage trial.

The FDA said the vaccine can be given to people 16 and older. Healthcare workers and elderly people in long-term care facilities are expected to be the main recipients of a first round of 2.9 million doses.

The US government said it will begin distributing the vaccine around the country immediately after FDA authorisation, and that the first inoculations would happen early next week.

Millions of Americans could begin getting vaccinated this month, especially if a second vaccine from Moderna Inc is quickly approved.

The Pfizer/BioNTech vaccine was first approved in Britain earlier this month, and UK residents began receiving the shots on Tuesday (local time). Canada also authorised the vaccine and expects to start inoculations next week.

Mexico and Bahrain have also approved the vaccine.

The FDA authorisation comes at a time when infections, hospitalisations and deaths are soaring to record levels in the US, which has failed to mount a coordinated effort to slow the spread of the virus.

Earlier this week, the one-day death total topped 3000, while hospital intensive care units across the country are nearing capacity, threatening to overwhelm healthcare systems.

Others with vaccines in advanced development include Moderna, which could win emergency US authorisation as soon as next week, AstraZeneca Plc with Oxford University, and Johnson & Johnson.

BioNTech began developing the vaccine in January, using a technology called synthetic messenger RNA (mRNA) that had yet to produce an approved product.

The technology uses a chemical messenger to instruct cells to make proteins that mimic part of the new coronavirus, which the immune system learns to recognise as an invader. BioNTech struck a development deal with Pfizer in March.

The vaccine comes with complex distribution challenges as it must be shipped and stored at -70 C, requiring specialised ultra-cold freezers or supplies of dry ice.

Moderna’s vaccine employs the same technology but does not need to be stored at sub-Arctic temperatures.

The US quest for a vaccine has been the central response to the pandemic from a Trump administration that has mostly otherwise left states to fend for themselves.

It has said it will have enough to supply all of the 330 million US residents who wish to be vaccinated by the middle of 2021.

-AAP