By Michael Balsamo and Zeke Miller

A person in California who had been vaccinated against COVID-19 became the first in the U.S. to have an identified case of the omicron variant, the White House announced Wednesday as scientists continue to study the risks posed by the new virus strain.

Dr. Anthony Fauci told reporters the person was a traveler who returned from South Africa on Nov. 22 and tested positive on Nov. 29. Fauci said the person was vaccinated but had not received a booster shot and was experiencing “mild symptoms.”

The Biden administration moved late last month to restrict travel from Southern Africa where the variant was first identified and had been widespread. Clusters of cases have also been identified in about two dozen other nations.

“We knew that it was just a matter of time before the first case of omicron would be detected in the United States,” Fauci said.

He said the person was improving and added, “I think what’s happening now is another example of why it’s important for people to get vaccinated. But also boosting. Boosting is very important.”

Officials said they had contacted everyone who had close contact with the person and they had all tested negative.

Genomic sequencing was conducted 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 U.S. testing rules for travelers from overseas, including requiring a test for all travelers within a day of boarding a flight to the U.S. regardless of vaccination status. It was also considering mandating post-arrival testing.

Officials said those measures would only “buy time” for the country to learn more about the new variant and to take appropriate precautions, but that given its transmissibility its arrival in the U.S. was inevitable.

Much remains unknown about the new variant, including whether it is more contagious than previous strains, whether it makes people more seriously ill, and whether it can thwart the vaccine. Fauci, the top U.S. infectious disease expert, said more would be known about the omicron strain in two to four weeks as scientists grow and test lab samples of the virus.

California’s Department of Public Health credited the state’s “large-scale testing and early detection systems” for identifying the case.

“We recognize that everyone is exhausted, and the news of a new variant can be overwhelming. It is important that we collectively focus on the things we know prevent the spread of COVID-19, and its variants,” state public health officials said in a statement.

The announcement of the first U.S. case comes before President Joe Biden plans to outline his strategy on Thursday to combat the virus over the winter. Biden has tried to quell alarm over the omicron variant, saying it was a cause for concern but “not a cause for panic.”

Biden and public health officials have grown more urgent in their pleas for more Americans to get vaccinated — and for those who have been vaccinated to get booster shots to maximize their protection against the virus.

Updated on December 1, 2021, at 3:45 p.m. ET with the latest details.

Share:
More In Science
Moderna Seeks FDA Authorization of Omicron-Specific Booster
The pharmaceutical giant Moderna says its updated 'bivalent' booster shot provides a stronger immune response against the Omicron variant of COVID-19 specifically. This week, Moderna plans to submit preliminary data to U.S. health officials in the hopes that its new booster will be available later this summer. Dr. Sampson Davis, emergency medicine physician, joins Cheddar News to discuss.
JWST's Gregory Robinson Expects to See 'Universe Different' in New Images
NASA has announced that the first official full-color images will be beamed back to Earth from the James Webb Telescope on July 12. Gregory L. Robinson, the director of the James Webb Space Telescope Program in the NASA Science Mission Directorate, joined Cheddar News to discuss the anticipated image drop. “We expect to see the universe different," he said. "Webb will allow us to see much, much clearer and deeper into the universe."
Human Evolution Speeding Up; Advancements in Genetic Engineering
On this episode of Cheddar Reveals, Professor Laurence Hurst, Director of The Milner Centre for Evolution, discusses the mystery of human evolution that's still baffling scientists: why are humans still evolving, and why has the process sped up? Neville Sanjana, faculty member at NY Genome and New York University, breaks down the latest innovations in CRISPR genetic engineering and its applications from 'designer babies' to curing genetic conditions and diseases; Cheddar gets a look at Curiosity Stream's 'The Butterfly Effect.'
Editing the Human Genome
Neville Sanjana, faculty member at NY Genome and New York University, joins Cheddar Reveals to break down the latest innovations in CRISPR genetic engineering and its applications from 'designer babies' to curing genetic conditions and diseases.
Why Humans are Evolving Faster Than Ever Before
Professor Laurence Hurst, Director of The Milner Centre for Evolution, joins Cheddar Reveals to discuss the mystery of human evolution that's still baffling scientists: why are humans still evolving, and why has the process sped up?
'Designed to Disappear': Loliware's Seaweed-Based Straws Offer Eco-Friendly Alternative
It can be tough to make sustainable choices, and even harder when sustainable materials don't hold up. Loliware has a solution to the plastic straw problem: its seaweed-based straws are stronger than paper alternatives and once used, can be composted and return to the earth or sea without causing harm. Sea Briganti, CEO of Loliware, joins Closing Bell to discuss the tech behind the straws, new product launches, and more.
Anja Health Raises $4.5 Million to Offer Parents Technology to Freeze Umbilical Cord's Stem Cells for Future Disease Treatment
Umbilical cord blood banking platform Anja Health raised $4.5 million dollars in a seed round led by Seven Seven Six, a venture capital firm founded by Reddit co-founder Alexis Ohanian. Anja Health offers a personalized, doctor-backed cord blood bank, which lets new parents freeze stem cells from their child's umbilical cord so they can be used to treat diseases in the future. It's a process Anja has called 'Hollywood's best-kept secret,' as celebrities like Kylie Jenner, Serena Williams, and more have all banked their umbilical cord blood. Kathryn Cross, the founder of Anja Health, joins Cheddar News' Closing Bell to discuss.
Calls Grow for Social Media to Flag Threats in Wake of School Shooting
After learning that the suspect in the Uvalde school shooting posted about his intentions on Facebook, activists are urging social networks to make changes. Lena Derhally, a licensed psychotherapist and author of "The Facebook Narcissist," joined Cheddar News to discuss the role social media plays in school shootings. "They're not really invested in taking down hateful content," she said about social platforms."In regards to the shooting, it was 15 minutes before that actual threat. It would be pretty hard for a social media company to trace that threat that quickly. But what they can do better is take down threats and hateful content much faster and more than they're doing now."
Load More