An updated version of Moderna’s Covid vaccine provides an eightfold increase in the level of antibodies to the Omicron variant, according to early experimental results, which raises hopes for a booster once a year to protect against the disease.
The vaccine is the first “bivalent” formulation that combines protection against Omicron and the original strain of coronavirus, and is the company̵[ads1]7;s leading candidate for upcoming autumn booster programs.
Dr. Paul Burton, Moderna’s chief physician, said the new vaccine increased antibody levels to such an extent that one boost a year may be enough, unless a significantly different variant requires the vaccine to be redesigned.
“The data we are showing today is very important because we are getting a very strong antibody response to Omicron,” he said. “For the first time, we can really look at the potential for just a once-a-year boost, because we can get people to such a high level that they will take longer to decay.”
The new vaccine, called mRNA1273.214, combines 25 micrograms of the original Moderna Covid vaccine with 25 micrograms of vaccine specifically targeted at the Omicron variant. In the Phase 2/3 trial, the 50mcg injections were given to 437 people who had already received two primary jabs and a booster of the original Moderna vaccine earlier in the pandemic.
The company has not released complete data from the trial, but according to a press release, the antibody levels against Omicron increased eight times during the first four weeks in people who received an injection of the new vaccine – their fourth in total.
About a quarter of those who participated in the trial had previously been infected with Covid, and in these, the antibody level rose further. Burton said that antibody levels above 400 units seemed sufficient to prevent infection, and in the trial the levels rose as high as 6,000 in those who had not been infected with Covid before, and 9,500 in those who had previously tested positive. “Both had a very good, fast, robust increase in antibody levels,” Burton said.
The first Omicron variant, called BA.1, appeared late last year and fueled severe waves of Covid around the world. Although less severe than some previous variants, its high transmissibility meant that it was still able to increase hospitalizations and deaths and put intense pressure on health systems.
Since the first wave of Omicron swept through the UK in December and January, even more transmissible sub-variants have emerged. Following a wave of so-called BA.2 Omicron this spring, two more variants, known as BA.4 and BA.5, have begun to gain ground.
Modern’s bivalent vaccine targets the BA.1 variant, but Burton said that although there was some reduction in protection against newer Omicron variants, it should still offer good long-term protection. “I feel confident it will hold up against the family right now,” he said.
Moderna intends to apply for approval from medical regulators in the coming weeks, including the UK’s Medicines and Healthcare Products Regulatory Agency, with a view to delivering the vaccine to this autumn’s booster program.
“We have started producing it and we will definitely plan to have it ready for the UK, Europe, USA and countries around the world, in very large supply,” said Burton.
If the booster provides years of protection against Covid, it could pave the way for dealing with the disease in a similar way to the flu, where strains are continuously tracked to identify which ones to go into next year’s season shot.
“To be able to move on, we have to get to a world that we do with the flu, where we see the new strain, we put it into the new vaccine, we can do it pretty quickly, and we can adapt much faster, “in Burton.