White House chief medical advisor Dr. Anthony Fauci said Tuesday that the United States has yet to confirm a case of the highly mutated Omicron COVID-19 variant, which has been detected in more than 20 countries so far.
The variant, which was first detected in South Africa about a week ago, has more than 30 mutations to the spike protein of the original SARS-CoV-2 genome, according to Fauci, which is the part of the virus that binds to human cells, causing infection. This level of mutation has alarmed global health officials due to the risk that Omicron may be more contagious than the highly transmissible Delta variant and possibly reduce the efficacy of available vaccines.
"This mutational profile is very different from other variants of interest and concern," Fauci said during the White House COVID-19 task force briefing on Tuesday. "Although some mutations are also found in Delta, this is not Delta; it's something different.
Fauci noted that several of the mutations on the spike protein have yet to be identified by scientists, meaning health officials do not know how Omicron spreads or behaves when compared to other variants. Other identifiable mutations on Omicron are associated with increased transmissibility and immune evasion, Fauci added.
U.S. Centers for Disease Control and Prevention (CDC) Director Dr. Rochelle Walensky said that the federal government is actively looking for the Omicron variant in the United States.
"Right now, there is no evidence of Omicron in the United States," Walensky told reporters. "The Delta variant remains the predominant circulating strain, representing 99.9% of all sequences sampled."
Walensky added that the CDC is expanding a surveillance program with XpresCheck to JFK, San Francisco, Newark, and Atlanta airports, which are four of the busiest international hubs in the U.S. The program allows for increase COVID testing, which will increase the CDC's capacity to identify incoming COVID-19 cases on arrival to the country, Walensky said.
Beyond the U.S. federal government, vaccine makers are also preparing to combat the Omicron variant. Both Chief Executives of Pfizer (NYSE: PFE) and Moderna (NASDAQ: MRNA) told CNBC's "Squawk Box" on Monday that they are working to determine how Omicron affects to their current COVID vaccines.