Though booster doses of current vaccines can foil the ultra-transmissible omicron coronavirus variant, a towering wave of omicron cases may peak in the US as soon as January, officials warn.
Scientists are still racing to fully understand the variant, which first gained international attention in late November. But a few things are becoming increasingly clear: the variant spreads stunningly fast, and it can largely circumvent protection from two vaccine doses. However, people who have received a third vaccine dose are well-protected against severe disease.
In a White House press briefing Wednesday, top infectious disease expert Anthony Fauci reviewed the early laboratory and real-world data on vaccine effectiveness. Numerous laboratory studies have all shown that levels of neutralizing antibodies from two doses of a vaccine are significantly lower against omicron—potentially so low that they do not protect against the variant. But studies looking at neutralizing antibodies after a third dose consistently find a substantial increase in protection. One study found a 38-fold rise in the level of neutralizing antibodies against omicron after a third dose of an mRNA vaccine.
Fauci also presented fresh, unpublished data from the National Institutes of Health, which found that a third dose of a Moderna vaccine restored neutralizing antibodies "well within the range of neutralizing omicron," Fauci said.
The laboratory findings are bearing out in real-world clinical data, Fauci noted. Researchers in South Africa reported this week that protection against infection from two doses of the Pfizer-BioNTech vaccine fell from 70 percent to 33 percent amid the omicron wave. But data from the United Kingdom found that getting a Pfizer-BioNTech booster dose restored protection, increasing vaccine effectiveness to 75 percent against symptomatic infection.
The findings have put a damper on the race to develop an omicron-specific vaccine dose, which Moderna and Pfizer/BioNTech have said they're working on in case one is needed.
"Our booster vaccine regimens work against omicron," Fauci concluded. "At this point, there is no need for a variant-specific booster."