Moderna has said that its new two-strain Covid-19 booster increases people’s immunity to the dominant Omicron variant, strengthening the company’s hopes of rolling it out as a fourth dose in late summer.
The US biotech company is the first to report preliminary results from a clinical trial of a vaccine targeted at Omicron. It said on Wednesday that the experiment showed that the “bivalent booster” – which contains the genetic code for the Omicron variant and the original strain of the virus – was safe and well tolerated.
Modern bivalent boosters 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 individuals who received a booster shot of Moderna’s existing vaccine.
The booster responded just as well to the original strain of the virus as its previous vaccine, and the candidate should provide more durable protection against concern variants, Moderna added.
In a conference call with investors, Stephen Hoge, Moderna’s president, said the new data showed that the bivalent booster was “significantly superior” in terms of the neutralizing protection it offered against Omicron and that it was “clearly time” to update vaccines.
Moderna shares closed nearly 2.2 percent higher in trading in New York on Wednesday.
Darius Hughes, Modern’s UK general manager, said the company was “very, very pleased” with the results, which showed that the new vaccine would provide “much better protection for the autumn and winter booster campaign”.
Many governments have not decided who will receive a fourth dose this fall and whether to provide a booster targeted at Omicron. The United States and the United Kingdom have already offered fourth dose to some of the most vulnerable groups, including the elderly. In April, EU regulators said it was too early to recommend a fourth dose to the general public.
Hughes said there was “some appetite” in the UK for switching to the vaccine, which 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 have to scale up production and switch from producing the original vaccine. Hughes said the switch was an “interesting challenge” but that the company had already spread its production around the world so it could move “fairly quickly”.
Experts continue to disagree on whether annual boosters targeting variants will be needed to combat Covid, with some noting that existing vaccines continue to offer strong protection against serious illness and hospitalization.
Others say, however, that a new booster could potentially boost immunity to the Omicron variant, which continues to spread rapidly in waves around the world.
“I would be cautiously optimistic that this bivalent vaccine will at least be a little more effective against Omicron than the original vaccine, but it’s too early to talk about it being any kind of game-changer,” he 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 recognized growing vaccine fatigue among the public.
At a June 28 meeting, advisers to the U.S. Food and Drug Administration are scheduled to discuss whether the current Covid vaccines should be modified and which strain of the virus they should target.
This article has been modified to reflect the increase in immunity that the booster provides.
