Moderna reports positive data for new Covid booster targeting Omicron variant

Moderna has said its new two-strain Covid-19 booster increases people’s immunity against the dominant Omicron variant, bolstering the company’s hopes to roll it out as a fourth dose in the late summer.

The US biotech company is the first to report preliminary results from a clinical trial of a vaccine targeted to Omicron. It said on Wednesday that the trial showed the “bivalent booster” — which contains the genetic code of the Omicron variant and the original strain of the virus — was safe and well tolerated.

Moderna’s bivalent booster elicited an eight-fold increase in antibodies to tackle the Omicron variant, compared to pre-booster levels, when administered as part of a four dose regimen. It produced 1.75 times more antibodies than people who received a booster shot of Moderna’s existing vaccine.

The booster responded to the original strain of the virus just as well as its previous vaccine and the candidate should provide more durable protection against variants of concern, added Moderna.

On a conference call with investors Stephen Hoge, Moderna’s president, said the new data demonstrated that the bivalent booster was “significantly superior” in terms of the neutralising protection it offered against Omicron and it is “clearly time” to update the vaccine.

Moderna shares rose by more than 7 per cent to $152.51 in early trading, compared to a 0.3 per cent rise in the Nasdaq Composite Index.

Darius Hughes, Moderna’s UK general manager, said the company was “very, very pleased” with the results, which showed the new vaccine would offer “much better protection for the autumn and winter booster campaign”.

Many governments have not decided who should receive a fourth dose in the autumn, and whether to provide a booster targeted at Omicron. The US and the UK have already offered fourth doses to some of the most vulnerable groups, including the elderly. In April, regulators in the EU said it was too early to recommend fourth doses for the general population.

Hughes said there was “some appetite” in the UK for switching to the vaccine that was better at targeting Omicron, which the country could do within the terms of its existing contract with Moderna.

If the bivalent vaccine is approved, Moderna will need to scale up manufacturing, switching from producing the original vaccine. Hughes said making the switch was an “interesting challenge” but that the company had already spread its manufacturing around the world so it could move “pretty quickly”.

Experts remain divided over whether annual boosters targeting variants will be required to combat Covid, with some noting that existing vaccines continue to offer strong protection against severe disease and hospitalisation.

However, others say a new booster could potentially boost immunity against the Omicron variant, which continues to spread rapidly in waves around the world.

“I would be cautiously optimistic that this bivalent vaccine will be at least a little more effective against Omicron than the original vaccine, but it’s far too early to talk about it being any sort of game-changer,” said David Dowdy, an epidemiologist at Johns Hopkins School of Public Health.

Pfizer is also pushing ahead with plans to develop an Omicron-specific booster shot that can provide better protection against new variants, but it has acknowledged growing vaccine fatigue among the public.

Advisers to the US Food and Drug Administration are, at a meeting on June 28, scheduled to discuss whether the current Covid vaccines should be modified and which strain of the virus they should target.

This article has been amended to reflect the increase in immunity provided by the booster.