A medical worker wearing personal protective equipment (PPE) inserts a Covid-19 test tube into a box at a test site at Alemany Farmers Market in San Francisco, California, November 19, 2020.
David Paul Morris | Bloomberg | Getty Images
Researchers at Stanford University have identified five new cases of the “double mutant” strain of Covid-19 that was recently discovered in the San Francisco Bay Area. Doctors suspect it may be more contagious and may be resistant to existing vaccines.
The new variant was born in India, where it is credited with a recent 55% increase in cases in the state of Maharashtra, home in Mumbai, after months of declining cases.
It contains two key mutations, which scientists call E484Q and L452R, which were found separately in other variants, but not together in a single strain, according to Dr. Benjamin Pinsky, medical director of the Stanford Clinical Virology Laboratory. who discovered the new variant in the USA
“There is a decent amount of information about how these mutations behave alone in viruses, but not in combination,” Pinsky said in an interview.
In other embodiments, the L452R mutation has been shown to make the virus more transmissible. There is also evidence that antibodies do not recognize this mutation, which has been found in other strains to reduce the effectiveness of vaccines.
The E484Q mutation has also been shown to be less susceptible to neutralizing antibodies, which help fight coronavirus. It is still too early to know if the mutation makes the virus more contagious.
But you would expect an increase in transmission as well as a reduction in antibody neutralization in combination with the L452R, Pinsky said.
If the mutation makes the virus more resistant to antibodies, it could reduce the effectiveness of both vaccines, as well as antibody treatments that have become a critical tool for doctors in the fight against Covid-19, according to Pinsky.
“I suspect that existing vaccines will be a little more effective in preventing infection with this new variant,” he said, “but all vaccines are extremely effective in preventing hospitalizations and deaths.”
Eli Lilly’s treatment with bamlanivimab antibodies has been shown to be less effective in treating strains containing E484Q or L452R mutations. U.S. health regulators stopped distributing antibody treatment last month, saying it is not as effective against new variants.
The mutant double variant “has undergone mutations in the scariest place to have a mutation – the receptor binding domain, in which the virus is used to attach to cells in our body to enter,” said Peter Chin-Hong. an expert in infectious diseases. at the University of California San Francisco. “The mutations are identical or extremely similar to the mutations in the variants we already know that have been scientifically proven to be more transmissible and / or avoid vaccines. Therefore, many believe that this Indian variant will have these superpowers as well.”
Tom Kenyon, director of health at Project HOPE and former director of global health at the Centers for Disease Control and Prevention, said scientists are finding more mutations, at least in part, because the new CDC director, Dr. Rochelle Walensky, has agency to increase oversight. “So the more we look for, the more we’ll find them,” he said.
“There is something in the ‘double’ world that scares people and makes them look doubly bad,” Kenyon said in an interview. “Any mutation that affects transmissibility or viral replication would be dangerous.”
There is a possibility that the new variant will remain in the Bay area, unlike variant B.1.1.7 in the United Kingdom, which has become the predominant strain almost everywhere it goes, Chin-Hong said.
“If the British version entered a boxing ring with the Indian version, the British version will probably come out victorious. But only time will tell,” Chin-Hong said.
The longer it takes to vaccinate the world, the more opportunities the virus has to move into even worse strains, scientists say. The CDC’s Walensky warned of “imminent fatality” in the United States, while states lift Covid-19 restrictions. She urged people to get vaccinated and continue to comply with public health measures, including wearing masks and practicing social distancing.
“The variants that scare me the most are the ones that haven’t been invented yet … as the virus reproduces, we’ll continue to see these escape mutants,” Chin-Hong said. “We need global vaccination equity and continued fight against pandemic fatigue.”
California is set to lift most Covid restrictions by June 15, but still intends to maintain a masked mandate.