The U.S. has detected the nation's first case of the omicron variant of the coronavirus in California, the Centers for Disease Control and Prevention (CDC) said Wednesday.
The individual is a fully vaccinated San Francisco resident who returned from South Africa on November 22, the CDC said. The person had mild symptoms, which are improving, and is self-quarantining.
All close contacts have also tested negative, the CDC added.
During a press briefing shortly after the case was disclosed, chief White House medical adviser Anthony FauciAnthony Fauci Auschwitz Memorial says RFK Jr. speech at anti-vaccine rally exploits Holocaust tragedy Thousands descend on DC for anti-vaccine mandate rally Sunday shows - Russia standoff over Ukraine dominates MORE urged Americans to get vaccinated against COVID-19 and said that those who are eligible should get their booster shots, describing the vaccines as the best protection against the virus and the omicron variant.
“We know what we need to do to protect people,” Fauci told reporters while encouraging Americans to wear masks in congregate settings to prevent the spread of the virus.
"[T]he fact is that people should wind up getting vaccinated and boosted if they’re eligible for a boost. I keep coming back to that because that’s really the solution to this problem," Fauci said.
He said the infected individual had not received a booster.
White House press secretary Jen PsakiJen PsakiBiden: A good coach knows when to change up the team Virginia's Youngkin gets the DeSantis treatment from media On student loans, Biden doesn't have an answer yet MORE also told reporters that President BidenJoe BidenUS threatens sweeping export controls against Russian industries Headaches intensify for Democrats in Florida US orders families of embassy staff in Ukraine to leave country MORE has been briefed on the omicron variant, noting that he meets with his medical team on a daily basis. Biden is slated on Thursday to outline plans to combat the coronavirus, and particularly the omicron and delta variants, during the winter months.
The person entered the U.S. four days before South Africa announced the discovery of the variant, and tested positive on Nov. 29, the same day the Biden administration's ban on travelers from eight African countries took effect.
The ban has come under fire from prominent health experts and former administration officials who say it is ineffective and punitive against African countries, especially as Western countries have failed to deliver needed vaccine supplies and logistics to the continent.
Fauci, however, defended the policy as necessary to buy time to better understand the new variant but said it was only temporary.
"We did struggle with that," Fauci said on Wednesday in response to a question from a reporter for Today News Africa. "We wanted to see if we could buy time, temporarily, so I do hope that this gets sorted out and lifted before it has any significant impact on your country."
Fauci also said he doesn't think Americans should be doing anything differently with their lives, and emphasized the importance of the mitigation strategies that are known to be effective — getting vaccinated, masking in crowded public spaces and physical distancing.
In a joint statement, California and San Francisco public health officials said the case was identified "thanks to California's large-scale testing and early detection systems."
The agencies said they are increasing testing at airports for arrivals from several countries identified by the CDC.
"We must remain vigilant against this variant, but it is not a cause for panic," the agencies said.
It was widely expected that the variant would be detected in the U.S. It has already been identified in other countries, including the U.K. and Canada, even after many nations moved to restrict travel from southern African countries, where the first known case was discovered at the end of last week.
“As the President said last Friday, it was only a matter of time before the first case of Omicron was detected in the U.S. We are prepared to meet this challenge with science and speed,” White House COVID-19 response coordinator Jeff ZientsJeff ZientsBiden says announcement coming next week on free high-quality masks Overnight Health Care — CDC won't change mask recommendation US ordering 500K more courses of AstraZeneca COVID-19 antibody cocktail MORE said in a statement.
“The President’s medical team continues to believe that existing vaccines will provide some level of protection against severe illness from Omicron, and individuals who have gotten boosters have even stronger protection. As such, we urge all adults to get their booster shots and to get themselves and their kids vaccinated, if they haven’t already,” Zients continued.
Officials say it will take at least two weeks to have a better understanding of the transmissibility and severity of omicron and the degree to which vaccines protect against it.
In the meantime, the Biden administration is working with the three vaccine manufacturers to prepare for the possibility that vaccines will need to be adjusted in order to provide protection against the new variant, but any changes will take time.
Brett Samuels contributed.
Updated at 11:20 p.m.