The US biotech company Moderna has said that a booster dose of its COVID-19 vaccine appears to protect against the Omicron variant, according to early laboratory tests.
The company said on Monday that its current vaccine would continue to be its “first line of defence against Omicron”, although Moderna still plans to develop a vaccine to protect specifically against Omicron.
The vaccine maker said it will continue to focus on its current version of the vaccine, mRNA-1273, in a decision motivated by the speed of the spread of Omicron
“What we have available right now is 1273,” Dr Paul Burton, Moderna’s chief medical officer, told the Reuters news agency.
“It’s highly effective, and it’s extremely safe. I think it will protect people through the coming holiday period and through these winter months when we’re going to see the most severe pressure of Omicron.”
While the company reported that a two-dose course of the vaccine generates low neutralising antibodies against Omicron, a 50 microgram booster increased neutralising antibodies by 37 times. Meanwhile, a 100 microgram booster dose resulted in an 80 times increase in antibodies from the initial two-dose course.
The data came from blood tests of people who had received the vaccine against a “pseudovirus” engineered to resemble the Omicron variant. It had not yet been peer-reviewed.
US regulators authorised the 50 microgram booster of Moderna’s vaccine in October. The first two shots of Moderna’s vaccine are both 100 micrograms.
The company said that the 100 microgram booster dose was generally safe and well-tolerated, although there was a trend towards slightly more frequent adverse reactions, which have included rare cases of heart inflammation, particularly in young men.
Omicron, a highly contagious variant first detected last month in southern Africa and Hong Kong, has raced around the globe and been reported in 89 countries, the World Health Organization (WHO) said on Saturday.
The UN health agency said the number of Omicron cases is doubling in 1.5 to 3 days in areas with community transmission, but noted that much remains unknown about the variant, including the severity of the illness it causes.