Moderna produces Covid-19 shot targeting variant found in SA
Moderna has become the first vaccine maker to produce a shot targeted at the virus variant discovered in SA, and will ship the doses to the US National Institutes of Health (NIH) to prepare for a clinical trial.
The Boston-based biotech is taking a three-pronged strategy to tackle 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 the existing shot to top up their immune response. It has now created a vaccine booster targeted at 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 CEO, said he was 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 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 institutions such as the World Health Organization (WHO) to declare which variants need to be tackled. “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 came after the US regulator last week urged vaccine makers to start studies of virus 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 shot 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 additional mutations would eventually render the vaccine ineffective.
Bancel said the world may be “a bit too optimistic” about the duration of the immune response from all the vaccines, none of which have been studied for more than a year.
He said it was likely that the immunity in the elderly would decline and need topping up.
Moderna also announced it was investing to expand production for 2022 to a total of 1.4-billion doses, translating to an increase of 200-million at the full dose.
However, because it is testing boosters at half a dose, these doses may end up stretching to more than 2-billion doses. Its vaccine is now author-ised for use in the US, UK and EU. The company is working to double its delivery to 40-million 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.