Mu COVID Variant Cases Are Highest in These Five States

The COVID-19 Mu variant has now been recorded in all 50 U.S. states after the World Health Organization labeled the strain a "variant of interest" last month.

Mu, or B.1.621, first identified in Columbia in January, has been detected in 5,659 sequences worldwide. Some 2,436 of these were detected in the U.S.

Although the variant remains relatively rare, accounting for less than one percent of cases across the U.S., early research has indicated the strain could be more transmissible and more resistant to vaccines.

California has reported the highest number of Mu variant samples in the country with 432 cases detected, according to Outbreak.Info, which uses data from the GISAID virus reporting network to provide open-source data on COVID-19 variants.

The L.A. Department of Health said the variant had "key mutations linked to greater transmissibility and the potential to evade antibodies" and Dr. Barbara Ferrer, director of L.A. County Public Health, urged residents to remain vigilant against the virus.

"The identification of variants like Mu, and the spreading of variants across the globe, highlights the need for L.A. County residents to continue to take measures to protect themselves and others," Dr. Ferrer said in a statement.

Florida has reported 308 cases of the Mu variant, the second-highest number in the country.

Dr. Jason Salemi, an epidemiologist with the University of South Florida, said he is "absolutely concerned" about Mu in light of its spread throughout the state.

"Cases of this variant have appeared all over the U.S., and it possesses mutations that suggest it has the potential to effectively combat what our immune systems are throwing at it," he told Newsweek. "If, in fact, the variant is capable of substantially reducing the effectiveness of vaccines in lowering the risk of severe illness...well, it's one of those situations that we've been worried about."

With 209 known cases, New York ranks third in the number of Mu samples detected as the state continues to battle high numbers of COVID-19 cases.

However, in an address on September 7, New York City's Department of Health and Mental Hygiene Commissioner Dr. Dave Chokshi said Mu has presented far less of a challenge to the city than the contagious Delta variant.

Alaska comes in fourth, with 149 recorded Mu cases. The strain is also most prevalent in Alaska compared to any other U.S. state, where it accounts for between 3 and 4 percent of all COVID-19 cases, according to Outbreak.Info.

Texas rounds out the top five states with 126 cases of the variant recorded as hospitals across the state continue to detect the strain.

Dr. Wesley Long, a clinical pathologist at the Houston Methodist Hospital, said staff had found cases dating back to May but believe they "probably don't have what it takes to overtake the juggernaut that is the Delta variant," given a general lack of spread.

Earlier this month, Dr. Anthony Fauci said that although Mu wasn't an "immediate threat," scientists will be "keeping a very close eye on it."

"This variant has a constellation of mutations that suggests that it would evade certain antibodies, not only monoclonal antibodies, but vaccine- and convalescent serum-induced antibodies," Fauci said.

The Delta variant is currently the dominant strain of COVID-19 in the U.S., accounting for more than 98 percent of circulating cases, according to data from the Centers for Disease Control and Prevention.

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File photo: A lab technician processes results of COVID-19 tests. MARVIN RECINOS/Getty Images