The U.S. Centers for Disease Control and Prevention announced on Wednesday that it has recorded the first case of the Omicron variant of COVID in a traveler who came to California from South Africa on November 22. The patient was fully vaccinated against COVID.

"The individual, who was fully vaccinated and had mild symptoms that are improving, is self-quarantining and has been since testing positive," the CDC said in a news release. "All close contacts have been contacted and have tested negative."

According to The Blaze, the first Omicron case was confirmed using genomic sequencing at the University of California-San Francisco. White House chief medical advisor Dr. Anthony Fauci told reporters during a press briefing that the Omicron case patient, who was not identified, tested positive for COVID on November 29 and was fully vaccinated but had not received a booster shot.

"We feel good that this patient not only had mild symptoms but actually the symptoms appear to be improving," Dr. Fauci remarked, adding that the Omicron case patient is self-quarantining and all of the patients' close contacts have been contacted and tested negative for coronavirus.

The White House issued a statement on Wednesday, saying, "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."

The White House continued to push for more inoculations, as well as booster shots for those who are eligible to get them to protect from the Omicron variant of COVID. The Omicron variant was tagged by the World Health Organization as a "variant of concern" during Thanksgiving week and reported that it had a high number of mutations, suggesting that it may be more transmissible than the Delta variant, which was highly contagious, the New York Post reported.

WHO announced that there is a "very high" global risk of the new variant, but scientists are yet unsure if existing vaccines can offer reliable protection against the Omicron variant. Given the unknown factors of the Omicron variant, Dr. Fauci urged the public to continue mask wearing throughout the holidays, especially in indoor settings.

Adding to the increased concern over the Omicron variant is Moderna CEO Stéphane Bancel's recent statements about the efficacy of their vaccines in protecting against the new COVID variant. While reporting that Moderna scientists are still testing its COVID vaccines on the Omicron variant, Bancel said that "there is no world where [the effectiveness] is the same level."

"All the scientists I've talked to...are like, ''This is not going to be good,'" Bancel said, as reported by CBS News. She said, however, that the company needs to "wait for the data" before coming to any conclusions on the Moderna COVID vaccines' efficacy in the face of the Omicron variant. Health authorities reported that the Omicron variant features an "unprecedented number" of mutations, even compared to the Delta variant, which makes up most if not all U.S. cases today.

Bancel told the press on Monday that Moderna will need months before it ships a newly formulated COVID vaccine that covers the Omicron variant. Pfizer, on the other hand, said it could release an Omicron-compatible COVID vaccine in "approximately 100 days," subject to approval by the U.S. Food and Drug Administration.