FDA okays Moderna, J&J COVID jab boosters, plus ‘mix and match’

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The FDA has authorised booster shots with Moderna and Johnson & Johnson’s COVID-19 vaccines, a month after giving the go-ahead to a third-dose of Pfizer/BioNTech’s shot.

It has also authorised the use of different jabs as boosters than those people received for their primary vaccination – the so-called ‘mix and match’ strategy – on the back of clinical results suggesting this can increase antibody counts.

As with Pfizer/BioNTech’s Comirnaty vaccine, a third dose of Moderna’s mRNA-1273 has been cleared for use in people aged over 65 – a last six months after the primary course – as well as for younger adults who are at high risk of severe covid or may be exposed to SARS-CoV-2 as a result of their living or work environment.

The situation is a little different for J&J’s Ad26.COV2.S vaccine, which is initially administered as one rather than two doses.

Last week, FDA advisors recommended a second dose of J&J’s shot to all recipients aged over 18, at least two months after the primary dose, recognising that its efficacy is lower than the other two vaccines. The FDA has followed that advice.

“The available data suggest waning immunity in some populations who are fully vaccinated,” commented acting FDA commissioner Janet Woodcock on a media call.

“The availability of these authorized boosters is important for continued protection against COVID-19 disease,” she added.

The authorisations mean that all three of the COVID-19 shots used in the US vaccination programme can now be used in booster campaigns, pending the outcome of a Centre for Disease Control and Prevention (CDC) advisory committee meeting – due to take place later today – on how they should be deployed.

That could include specific recommendations on mixing and matching different vaccines. The FDA has given the go-ahead to that approach but hasn’t given any indications of which combinations should be used.

Woodcock said it is likely that many people would get the same vaccine as their primary course, emphasising that the FDA “does not have preferential recommendations on boosters.”

One issue that has emerged is that Moderna’s booster dose is half that used in the initial regimen, which has raised questions about whether it should be offered as an option to those who initially received the J&J or Pfizer/BioNTech shots.

Assuming the CDC backs a rollout, booster doses are expected to be offered quickly to the 15 million Americans who received a J&J shot as their primary, and the 69 million inoculated with the Moderna jab.

The CDC’s decision could be informed by the ongoing situation in the UK, which has seen cases of COVID-19 climb sharply of late. Some commentators suggest this is because the country was very quick off the mark with its vaccination programme, so more people may now be seeing declining protection.

Daily UK infections have been above 40,000 for eight days straight, and approached 50,000 yesterday.

The UK government resisted calls for a reintroduction of restrictions such as mandatory face masks, insisting that the key to keeping COVID-19 under control is vaccination, specifically boosters for 30 million people and a single dose for 12- to 15-year-olds.