The top U.S. infectious disease expert said Tuesday that vaccinated Americans have "some degree of protection" against the new omicron variant of the coronavirus, but that scientists will not know for a few weeks how vaccines may need to be altered to best fight it.
Dr. Anthony Fauci, President Joe Biden's top medical adviser, said at a White House coronavirus news briefing that the omicron "mutation profile is very different from other variants" of the coronavirus.
While he said the three existing vaccines used in the U.S. could prevent people who have been inoculated from getting seriously ill from the omicron variant, it "remains uncertain … speculative" whether they will fully work against people getting sick.
"We believe it is too soon to tell about the severity" of the omicron variant, he said. "We should have a much better idea in the next few weeks."
To date, he said, 226 cases of the omicron variant have been identified in 20 countries across the globe, but none so far in the United States. Health officials, however, say they assume the variant eventually will spread to the United States.
"We are actively looking for the omicron variant in the U.S.," said Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention.
Stephane Bancel, chief executive of Moderna, which produces one of the vaccines used in the U.S., predicted in an interview with the Financial Times that existing vaccines would be much less effective in combating the omicron variant than the previous four variants of the coronavirus.
"There is no world, I think, where (the effectiveness) is the same level … we had with delta," Bancel said, referring to the highly contagious variant that is the predominant strain throughout the U.S. and was first detected in India in late 2020.
His comments sent U.S. stock indexes tumbling, as investors feared the effect of the omicron variant on the world economy, in which many countries are still struggling from the coronavirus onslaught that started in early 2020.
Bancel said it could take months for pharmaceutical companies to manufacture effective new vaccines to deal with the specific molecular makeup of the omicron variant.
Dutch officials said Tuesday that they detected the omicron variant in tests almost two weeks ago, days earlier than when two flights from South Africa transported infected passengers to the Netherlands.
Walensky said 45 million adults are unvaccinated in the U.S., and millions more children, ages 5 to 18, are eligible to get shots, but their parents have yet to get them inoculated.
In addition, Jeffrey Zients, the White House COVID-19 response coordinator, said that 100 million vaccinated people in the U.S. are eligible for booster shots but have yet to get them.
He, too, said that vaccinations provide "some protection" against the omicron variant and that "boosters help that."
"We want to make sure Americans are doing all they can to protect themselves," he said.