A new “double mutant” strain of the coronavirus has been discovered in San Francisco, marking the first time the variant, thought to be behind a surge of cases in India, has been identified in the United States.
The mutation is referred to as a “double mutant” because it carries two mutations that help the virus attach to cells, The San Francisco Chronicle reported.
The case is a patient from a Stanford Health Care clinic and likely occurred in Santa Clara County, according to the Chronicle. County health officials said they are not monitoring the new variant because it isn't on the Centers for Disease Control and Prevention's list of concern, according to the Chronicle.
One of the mutations in the new strain is similar to that found on both the variants first detected in Brazil and South Africa. The second mutation has been found in a variant in California. The mutation is believed to be more transmissible than the original strain of COVID-19, but it is not yet known if it is more resistant to vaccines.
Citing Peter Chin-Hong, an infectious diseases expert at the University of California San Francisco, the Chronicle says the variant is the first time two mutations have been detected in the same virus.
Initial results from trials conducted with vaccines currently approved for use in the U.S. have shown that vaccines are still effective against variants, and Chin-Hong said he was "optimistic" that they would also be effective against the "double mutant" strain as well.
Recall, media reports said last month a new "double mutant" variant of the coronavirus has been detected from samples collected in India.
The BBC reported on March 25 that Indian genome scientists have detected a so-called "double variant" of the novel coronavirus.
The government said that an analysis of the samples collected from the western state of Maharashtra showed "an increase in the fraction of samples with the E484Q and L452R mutations" compared with December last year.
"Such [double] mutations confer immune escape and increased infectivity," the health ministry said in a statement, according to the BBC.
Meanwhile, virologists reportedly say that such "double mutants" are not so rare.
