Moderna announced preliminary data on Monday that it said showed a third booster dose of its coronavirus vaccine appeared to significantly increase antibodies that can help fight off an infection with the Omicron variant. Moderna said lab tests showed Omicron-neutralizing antibodies were low after two doses of its jab, but 29 days after a booster dose of 50 micrograms, they increased about 37-fold.
The 50 microgram dose is given as a booster with the Moderna shot, but the company’s data showed that a full, 100 microgram booster dose increased antibody counts even more, around 83-fold.
“It’s highly effective, and it’s extremely safe,” Moderna’s chief medical officer Dr. Paul Burton said of the current vaccine in an interview with the Press Association. “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.”
Omicron has been reported in at least 89 countries and all but five U.S. states, and the number of cases is doubling every couple of days in places where there is community transmission, the World Health Organization said on Saturday.
Because of how quickly Omicron is spreading around the globe, Moderna said the current version of its vaccine would remain its “first line of defense against Omicron.” It plans to develop an Omicron-specific vaccine that will advance into clinical trials next year, however, “given the long-term threat demonstrated by Omicron’s immune escape.”
Moderna said there were more adverse reactions after the larger, 100 microgram booster dose in its lab trial, but that both were generally well tolerated.
Burton told the Press Association that it would be up to governments and regulators to decide which booster dosage they want to use going forward. U.S. regulators authorized a 50 microgram booster dose of the Moderna vaccine in October, but the first two doses of the vaccine are 100 micrograms.
The announcement from Moderna echoed similar news from Pfizer and BioNTech earlier this month, which manufactures the other mRNA vaccine authorized for use in the United States. Pfizer said that while two doses of its vaccine appeared not to offer sufficient protection against infection with Omicron, a third, booster dose raised antibody levels 25-fold.
“Although two doses of the vaccine may still offer protection against severe disease caused by the Omicron strain, it’s clear from these preliminary data that protection is improved with a third dose of our vaccine,” Pfizer chairman and CEO Albert Bourla said in a statement.
“Ensuring as many people as possible are fully vaccinated with the first two dose series and a booster remains the best course of action to prevent the spread of COVID-19,” he said.