Moderna has become the first vaccine maker to develop a jab that targets the South African coronavirus variant.
The Boston-based biotech has already shipped the raw materials to the US National Institutes of Health, which helped the firm study its first jab, to start human trials.
Dr Anthony Fauci, the US’ top Covid expert, and his team at the NIH will begin testing the vaccine in a small group of volunteers within weeks.
The booster dose will be given as a top-up to people who have already received Moderna’s original jab, which Britain has approved and ordered 17million doses of.
A Moderna source told MailOnline today the new vaccine would be in people’s arms by this winter at the latest, if trials are successful.
Lab studies have shown the firm’s original vaccine was less effective against the South African strain, known scientifically as 501.V2. While it still worked, it only induced one-sixth of the antibodies that it did against the original strain.
The finding raised concerns that people’s immunity could fade over time or that newer, further evolved strains could hide from the vaccine completely.
The new booster jab targets the E484K mutation found on the South African variant’s spike protein. The alteration is also present on a troubling strain in Brazil and has been cropping up on various variants in Britain.
Stephane Bancel, Moderna’s chief executive, said the firm had become the first to develop the targeted vaccine because it had the ‘muscle’ to respond to variants. Moderna is using brand-new mRNA technology which can be engineered more easily than traditional vaccines.
Moderna has become the first vaccine maker to develop a jab that targets the South African coronavirus variant (file)
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The announcement came after the medical regulator in the US urged vaccine makers to launch trials of vaccines that target new variants.
The Food and Drug Administration has said it will only need to see proof of the booster vaccines on hundreds of people, rather than tens of thousands like the original Covid jabs, to give them the green light.
And it added the studies would only need to last two or three months which is less than half the time of the original trials.
The South African variant caused international alarm when it triggered an explosion of cases in the country last autumn.
There are two key mutations on the variant that appear to give it an advantage over older versions of the virus – these are called N501Y and E484K.
Both are on the spike protein of the virus, which is a part of its outer shell that it uses to stick to cells inside the body, and which the immune system uses as a target.
They appear to make the virus spread faster and may give it the ability to slip past immune cells that have been made in response to a previous infection or a vaccine.
Public Health England has detected the mutant virus 217 times in the UK since late December.
So far all of Britain’s approved vaccines seem to work against the variant, according to early lab studies, but to what degree is still a mystery.
Pfizer and Moderna’s vaccines appeared to be able to neutralise the strain, but were far less potent, raising fears immunity could wane over time.
A small study of Oxford University/AstraZeneca’s jab on young people found it offered them minimal protection against mild coronavirus, although this is not the point of the vaccine, which is intended to prevent severe illness and death.
Johnson & Johnson’s single-dose vaccine, which is waiting approval, was shown to block 57 per cent of coronavirus infections in South Africa, which meets the World Health Organization’s 50 per cent efficacy threshold.
British scientists say there is no reason the South African strain will become dominant in the UK because it is not more infectious than the Kent one, therefore it does not have an ‘evolutionary edge’.
However, there are concerns that once the population has been vaccinated the South African strain could become more prevalent because of its antibody-resistant properties.
Meanwhile, Moderna also announced today it is experimenting with two other methods combat new Covid variants through vaccination.
It is also developing a vaccine that mixes its original vaccine with the new South African one which could be delivered as a single injection to protect against both variants.
And it’s looking into whether giving people who received both doses of its original vaccine another half-dose of that jab could give additional protection against new strains.
Mr Bancel, Moderna’s chief executive said he was concerned about new variants, warning that a lack of genomic sequencing in most countries meant mutant viruses could be rapidly spreading around the world right under scientists’ noses.
Moderna also announced it is investing to expand production for 2022 to a total of 1.4billion doses, up from a previous projection of 1.2bn.
Its vaccine is currently authorised for use in the US, UK and EU, but most of the doses have been deployed in America while the firm tries to scale up its European supply chain.
About 60 million Moderna doses have been shipped so far, of which 55 million have gone to the US and the rest to Europe. Britain is expected to start getting supplies within weeks.