The pandemic has taken yet another turn with the discovery of the Omicron variant. Mounting research has shown that the latest version of the virus is likely to be more contagious and make currently available vaccines less effective. And as more information comes in, Anthony Fauci, MD, chief COVID adviser to the White House, is warning fully vaccinated people that there’s still one major thing they need to do to protect themselves from the latest variant.
During an interview with CNN on Dec. 14, Fauci urged people who had already received their shots to get boosters in light of new studies covering the variant. The infectious disease expert said that the latest information presented “a very strong argument” in favor of seeking out the supplemental shots.
“Omicron is going to be a challenge because it spreads very rapidly, and the vaccines that we use—the regular two-dose mRNA—don’t do very well against infection itself. But particularly if you get the boost, it is pretty good,” he told CNN. “There is no doubt that the optimal protection is going to be with three doses of an mRNA.”
While some experts previously questioned whether or not a new specific vaccine would be needed to protect against the variant, Fauci argued that the tools to fight the latest viral offshoot are already in use. “Our booster vaccine regimens work against Omicron,” Fauci said during a White House COVID press briefing on Dec. 15. “At this point, there is no need for a very specific booster. And so the message remains clear: If you are unvaccinated, get vaccinated, and particularly in the arena of Omicron if you are fully vaccinated, get your booster shot.”
Fauci’s comments come just days after Pfizer and BioNTech revealed the results of lab experiments testing their vaccine’s effectiveness against the latest variant on Dec. 8. The company’s study found that blood samples taken from patients who had only received the initial two doses saw a 25-fold reduction in antibodies, which the companies said “may not be sufficient to protect against infection” from Omicron. However, samples taken from patients one month after receiving a booster shot of the vaccine saw an antibody response that was similar in strength to levels recorded against previous variants after the initial two shots, The New York Times reports.
The tests also suggest that T cells—a critical part of the immune response—did not appear to be affected by the high number of mutations observed on the Omicron variant’s spike proteins. According to the companies, this could mean that “vaccinated individuals may still be protected against severe forms of the disease” even if they’ve only received their initial shots.
During an interview with NBC’s Today on Dec. 8, Pfizer CEO Albert Bourla said that a vaccine booster “dramatically” improved the protection provided against the latest variant. “To make it clear for your audience, three doses against Omicron are almost equivalent to the [two] doses effectiveness we had against … the original variant,” he said. “You may need to go get the third booster faster, and that’s something that the health authorities should consider very carefully and make their recommendations,” he added. “But clearly, having two doses compared to nothing protects you way better than having nothing.”
Fauci also offered a relatively optimistic outlook on the variant but cautioned that things could turn out differently once Omicron surpasses Delta as the dominant variant.
“Whatever it is, the disease seems to be less severe. Whether it’s inherently less pathogenic as a virus or whether there’s more protection in the community, we’re just going to have to see when it comes in the United States,” he told CNN. “And for sure … it is going to be dominant in the United States, given its doubling time,” he predicted.