The United States has identified its first case of the Omicron variant, which has already been reported in more than a dozen other countries since the new coronavirus strain was first detected in southern Africa last week.
The infected patient—who is experiencing “mild symptoms”—is fully vaccinated, and returned to California from South Africa on Nov. 22, testing positive for the variant on Nov. 29, Dr. Anthony Fauci announced Wednesday.
During a White House press briefing on Wednesday, Fauci said that genomic sequencing of the sample at the University of California at San Francisco that was examined by the Centers for Disease Control confirmed the positive case. The individual is self-quarantining and all close contacts have so far tested negative, he said.
Fauci said that there was much to be learned about the new strain, but urged eligible Americans to “get boosted now,” adding that it was not immediately clear whether or not a variant-focused booster would be needed.
“When you get a high enough level of an immune response, you get spill-over protection, even against a variant that the vaccine wasn’t specifically directed at,” Fauci said, citing the vaccine’s enduring protection against severe disease with the Delta variant. He cautioned, however, that “we have to be prepared that there might be a diminution.”
Countries around the world have been scrambling to determine how best to respond to what the World Health Organization has characterized as the “very high” risk posed by the latest variant of the coronavirus which was first identified by researchers in South Africa.
According to the agency, which designated Omicron as a variant of concern on Friday, the strain features “a high number of mutations,” which have sparked worries about potential for “immune escape” and “higher transmissibility.”
The last coronavirus variant to receive a similar designation was Delta, which quickly took the world by storm after it was first identified in the United Kingdom in the spring.
The WHO cautioned on Monday that “considerable uncertainties” remain as health experts examine emerging evidence around the variant’s threat, just how transmissible it is, and how well existing vaccines protect against infection. It urged countries around the world to move quickly toward vaccinating more of their eligible populations while also beefing up testing.
“We don’t have enough information right now,” Fauci said, echoing the agency’s assertion to reporters on Wednesday. He added that while the molecular profile of the new strain could suggest that it may be more transmissible, experts are still collecting data to predict its impact.
“It is too early to say,” he said. “We’re really very early in the process.”
Late last week, researchers at the Botswana Harvard HIV Reference Laboratory sequenced the genes of coronaviruses from positive test samples and uncovered the concerning and previously unreported mutation. Since then, cases have been detected in Germany, Italy, Belgium, Israel, Canada, and Hong Kong, among others.
CDC Director, Dr. Rochelle Walensky, said during a White House news conference on Tuesday that the CDC had been “actively looking” for the Omicron variant but at the time added that there so far there was “no evidence” of it as the Delta variant remained the predominant strain representing 99.9 percent of all sequence sampled.
Since Omicron’s discovery, countries have banned passengers from southern Africa, citing a desire to combat the variant’s spread, with Japan, Israel and Morocco barring all foreign visitors. Biden on Friday announced a ban on travelers from eight countries in the region.
While some some officials have been accused of quickly blaming African nations for the variant, in spite of limited accessibility to vaccine doses across the continent, health officials in the Netherlands reported on Tuesday that the country had already logged a case of what has since been identified as an Omicron variant infection as early as Nov. 19. The case, along with a second on Nov. 23, predate the arrival of a pair of flights from South Africa that triggered a firestorm of targeted travel bans from the region.
Addressing the growing panic during a press conference on Monday, President Joe Biden foreshadowed what arrived just days days later:
“Sooner or later, we’re going to see cases,” he said. “This variant is a cause for concern—not a cause for panic.”