Moderna produces Covid-19 shot targeting South African variant

Moderna has become the first vaccine maker to produce a shot targeted at the virus variant discovered in South Africa and is shipping the doses to the US National Institutes of Health to prepare for a clinical trial. 

The Boston-based biotech is taking a three-pronged strategy to try to address concerns that its vaccine, along with several others, is less effective against the 501.V2 strain. 

The company has already begun giving previous trial participants a half-dose booster of of the existing shot to top up their immune response. It has now created a new vaccine booster targeted to the variant, also at half a dose. Anthony Fauci’s team at the NIH will begin testing it in phase 1 trial participants within weeks. 

Moderna is also creating the first multivalent vaccine, which includes the genetic code for the spike protein of both the original strain of the virus and the 501.V2 variant, in hopes of making it effective against both variants. The company’s technology has previously been used to combine up to six genetic sequences in a shot.

Stéphane Bancel, Moderna’s chief executive, said he was quite worried about the “evolution of mutants” beyond the existing variants, especially because a lack of genomic sequencing means it may not be clear what strains are already spreading. 

He said his company had built the “muscle” to respond to new variants, given its mRNA technology is the quickest and easiest to adapt. 

“We feel a very strong sense of responsibility to the world to chase any variant of concern,” he said, adding he would rather chase “too many” variants, creating vaccines that are not needed, than too few. 

Bancel said he would not wait for global institutions such as the World Health Organization to declare which variants need to be addressed. “If I’d waited even for the WHO to declare a pandemic to start thinking, ‘maybe we should do a vaccine’, we would not have shipped tens of millions of doses already,” he said. 

The announcement comes after the US regulator earlier this week urged vaccine makers to start studies of new variants. The Food and Drug Administration said it would only require studies of hundreds of people, lasting two or three months, for tweaked Covid-19 vaccines, rather than lengthy trials and a full application for an emergency use authorisation.

In lab studies, Moderna’s vaccine still worked against the 501.V2 variant, but it induced only one-sixth of the neutralising antibodies, raising concerns that immunity would wane over time — or that new mutations would eventually render the vaccine ineffective. 

Bancel said the world may be “a bit too optimistic” about the duration of immune response from all the vaccines, none of which have been studied for more than a year. He said it is likely that the immunity in the elderly will decline and need topping up. 

Moderna also announced it is investing to expand production for 2022 to a total of 1.4bn doses, translating to an increase of 200m at the full dose. However, because it is testing boosters at half a dose, these doses may end up stretching to more than 2bn doses. Its vaccine is currently authorised for use in the US, UK and EU.

The company is working to double its delivery to 40m a month by April. One bottleneck had been a lack of “fill and finish” capacity, where vaccine ingredients are put into vials, so Moderna has proposed increasing the number of doses per vial.

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