Moderna booster shot appears effective against Omicron variant, company says
Global News
Moderna says a 50 microgram booster dose of its COVID-19 vaccine increased neutralizing antibodies against the Omicron variant 37 fold.
Moderna Inc. said on Monday that a booster dose of its COVID-19 vaccine appeared to be protective against the fast-spreading Omicron variant in laboratory testing and that the current version of the vaccine would continue to be Moderna’s “first line of defense against Omicron.”
The vaccine maker said the decision to focus on the current vaccine, mRNA-1273, was driven in part by how quickly the recently discovered variant is spreading. The company still plans to develop a vaccine specifically to protect against Omicron, which it hopes to advance into clinical trials early next year.
“What we have available right now is 1273,” Dr. Paul Burton, Moderna’s Chief Medical Officer, said in an interview. “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.”
The company said a two-dose course of its vaccine generated low neutralizing antibodies against the Omicron variant, but a 50 microgram booster dose increased neutralizing antibodies against the variant 37 fold. A higher, 100 microgram booster dose of the same vaccine drove antibody levels even higher – more than 80 times pre-boost levels.
In Canada, regulators have approved use of Moderna’s vaccine as a booster. It has been approved for use as a half dose of the full vaccine; the National Advisory Committee on Immunization suggests vulnerable populations like the immunocompromised, can be given a full dose for a third shot.
The data, which has not yet been peer reviewed, tested blood from people who had received the vaccine against a pseudovirus engineered to resemble the Omicron variant. It is similar to data discussed last by top U.S. infectious disease expert Anthony Fauci.
Burton said it would be up to governments and regulators to gauge whether they want the enhanced level of protection that a 100 microgram dose might confer.
The company said that the 100 microgram dose was generally safe and well tolerated, although there was a trend toward slightly more frequent adverse reactions.
