A Covid-19 vaccine made by Moderna has been approved for use in the United States, with millions of doses to now be distributed immediately.
The Food and Drug Administration (FDA) authorised the US-made drug around a week after approving a vaccine by Pfizer/BioNTech, which is now being rolled out.
The US has purchased 200 million doses of the Moderna vaccine, with six million said to be ready to ship already.
Clinical trials of the vaccine found it had an efficacy of 94.1 per cent, and 100 per cent against severe Covid-19. The FDA said the benefits of the jab outweighed the risks for those aged 18 and up.
There have been concerns that a Covid-19 vaccine will not work as well on elderly people, much like the annual flu jab, but data from Moderna suggests that it is effective across all age groups.
Trial results also indicated that the vaccine is generally well tolerated and has no major safety concerns.
It works in a similar way to the jab from Pfizer/BioNTech vaccine, in that it provides the body with instructions to produce a small amount of a coronavirus protein. Once detected by the immune system, this leads to a protective antibody response.
However, Moderna’s vaccine does not require the same ultracold storage as Pfizer’s and can remain stable at normal fridge temperature for 30 days.
Trials on more than 30,000 people in the US have shown the jab to be 94.5 per cent effective in preventing coronavirus, and while this efficacy may drop over time, scientists have said the jab should protect against nine in 10 cases of Covid-19.
When will it arrive in the UK?
The government has signed a deal for seven million doses of the Moderna vaccine for use in the UK, amounting to enough for around 3.5 million people, who will each receive two doses.
Moderna is understood to be scaling up its European supply chain, but these doses are not expected to be available in the UK until spring at the earliest, according to the government.
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) has been conducting a rolling review of the vaccine.