Omicron arrives in the United States

The White House reported on Wednesday that a traveler who arrived in California from South Africa had tested positive for the new omicron variant of the coronavirus. Anthony Fauci, the top U.S. infectious disease official, said the person landed in California on Nov. 22 and tested positive on Nov. 29. The University of California, San Francisco, conducted genomic sequencing to identify the variant, and the Centers for Disease Control and Prevention confirmed the finding. The traveler was vaccinated against COVID-19 but had not received a booster shot. Fauci said the patient has mild symptoms and is recovering.

Is the omicron variant serious? Fauci and other health officials have said it will take two to four weeks for scientists to test the new strain. The variant’s high number of mutations could affect whether vaccines are effective against it, and companies like Moderna and Johnson & Johnson said they will adapt their vaccines if necessary. South Africa, which was first to report the variant, said new COVID-19 cases within its borders doubled on Wednesday alone. The CDC now requires a negative COVID-19 test for any international travelers to the United States, regardless of vaccination status. President Joe Biden, who is urging Americans to get vaccinated and get booster shots, is expected to announce a new U.S. strategy to combat COVID-19 on Thursday. The delta variant is still the dominant strain worldwide.

Dig deeper: Read my report in The Sift on omicron’s effect in South Africa.