White House chief medical advisor Dr. Anthony Fauci said Tuesday that 226 cases of the highly mutated omicron Covid-19 variant have been detected across 20 countries so far, but U.S. officials haven’t yet confirmed a case in the states.
The variant, which first emerged in South Africa about a week ago, has more than 30 mutations to the spike protein alone. That’s the key part of the virus that allows it to bind to human cells and infect the body and makes scientists worry that it will be far more infectious than the highly contagious delta variant that’s caused a surge in cases across globe in recent months.
“This mutational profile is very different from other variants of interest and concern, and although some mutations are also found in delta, this is not delta,” Fauci told reporters on a White House Covid-19 task force briefing. “These mutations have been associated with increase transmissibility and immune evasion.”
There are several other mutations to the virus that scientists haven’t seen before and don’t know how they will change how the virus behaves or spreads, he said.
U.S. officials have stepped up genomic sequencing of Covid cases in recent months, sequencing about 80,000 samples per week, up from about 8,000 a week earlier this year, said Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention.
She said the delta variant remains the predominant strain in the U.S., accounting for about 99.9% of all cases sequenced across the country.
“To be crystal clear, we have far more tools to fight the variant today than we had at this time last year,” Walensky said at the briefing.
Fauci said it’s too early to tell whether omicron will be more deadly than the delta variant. Reports of more mild symptoms in South Africa were in younger and healthier patients who would typically have milder Covid and are based on a small number of cases, he noted.
“It is very difficult to know whether or not this particular variant is going to result in severe disease,” he said. “Although some preliminary information from South Africa, suggests, no unusual symptoms associated with variant, we do not know and it is too early to tell.”