Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, listens during a press conference in the James S. Brady press conference room of the White House in Washington, DC, USA, on Tuesday, May 13 April 2021.
Leigh Vogel | Bloomberg | Getty Images
The new “mu” variant of Covid-19 is not an immediate threat to the United States, federal health officials said Thursday.
“We look at it, we take it seriously, but we don’t consider it an immediate threat at this time,” Dr. Anthony Fauci, chief medical adviser to the White House, at a press conference.
Mu, also known to scientists as B.1.621, was added to the WHO list of “interest” variants on Monday, the international health organization said in its weekly Covid epidemiological report released Tuesday in the afternoon.
“This variant has a constellation of mutations that suggests it would evade certain antibodies, not just monoclonal antibodies, but vaccine-induced antibodies and convalescent serum,” Fauci said. “But there isn’t a lot of clinical data to indicate that, it’s mostly in vitro lab data.”
Although Covid-19 vaccines were created with the original Covid strain in mind, vaccines are still very effective against the delta strain.
“Remember, even when you have variants that slightly decrease the effectiveness of vaccines, vaccines are still quite effective against variants at this point,” Fauci said.
Delta was a variant of interest until the WHO reclassified it in early May after preliminary studies found that it could spread more easily than other versions of the virus. Since then, this variant has been blamed for several major outbreaks around the world, including the United States.
The delta variant remains the dominant variant in the United States, as it covers more than 99% of new infections in the country. Fauci said the mu variant “is not even about to be dominant” in the US.
Mu was first identified in Colombia, but has since been confirmed in at least 39 countries, according to the WHO. Although the global prevalence of the variant between sequenced cases has decreased and is currently below 0.1%, its prevalence in Colombia and Ecuador has steadily increased, the agency warned.
“We’re looking at it very closely,” Fauci said.