The White House announced Wednesday that a person in California vaccinated against COVID-19 has become the first person in the United States to have a specific case of the omicron variant, as scientists continue to study the risks posed by the new virus strain.
Dr. Anthony Fauci told reporters that the person was a traveler who returned from South Africa on November 22 and tested positive for the virus on November 29. Fauci said the person had been vaccinated but had not received a booster dose and was experiencing “mild symptoms.”
The Biden administration moved late last month to restrict travel from South Africa where the alternative was first identified and spread widely. Clusters of cases have also been identified in about two dozen other countries.
“We knew it was only a matter of time before the first case of omicron was detected in the United States,” Fauci said.
He said the person is getting better and added, “I think what is happening now is another example of the importance of vaccinating people. But also of reinforcement. Reinforcement is very important.”
Officials said they have contacted everyone who has been in close contact with the person and have tested negative.
The genetic sequencing was performed at the University of California, San Francisco and the sequence was confirmed by the Centers for Disease Control and Prevention.
The Centers for Disease Control and Prevention is taking steps to tighten US testing rules for overseas travelers, including requiring testing for all travelers within one day of boarding a flight to the US regardless of vaccination status. It was also considering post-arrival testing.
Officials said these measures would only “buy time” for the country to learn more about the new variant and take appropriate precautions, but given its transmissibility in the United States, its arrival in the United States was inevitable.
Much remains unknown about the new variant, including whether it is more contagious than previous strains, whether it makes people more dangerous, and whether it could thwart a vaccine. Fauci, the top US infectious disease expert, said more will be known about the Omicron strain in two to four weeks as scientists grow and test samples of the virus in the lab.
The California Department of Public Health credited the state’s “extensive testing and early detection systems” for identifying the case.
“We recognize that everyone is stressed, and news of a new variant can be overwhelming. It is important that we focus collectively on the things we know are preventing the spread of COVID-19 and its variants,” state public health officials said in a statement.
The announcement of the first US case comes before President Joe Biden plans to outline his strategy on Thursday to combat the virus through the winter. Biden tried to calm the jitters about the omicron variant, saying it was a cause for concern but “not a cause for alarm.”
Biden and public health officials have become more urgent in their pleas for more Americans to get vaccinated — and for those vaccinated to get boosters to further protect them from the virus.