A medical worker wearing personal protective equipment (PPE) inserts a Covid-19 test tube into a box at a driving test site through the German Farmers Market in San Francisco, California on November 19. 2020.
David Paul Morris | Bloomberg | Getty Images
Researchers at Stanford University have identified five new cases of a “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 originated in India, where it is credited with a recent 55% increase in cases in the state of Maharashtra, home of Bombay, after months of declining cases.
It contains two key mutations, which scientists call E484Q and L452R, that have been found separately in other variants but not together in a single strain, according to Dr. Benjamin Pinsky, medical director of Stanford’s clinical virology lab, who discovered the new variant in the US
“There’s a fair amount of information about how these mutations in viruses behave on their own, but not in combination,” Pinsky said in an interview.
In other variants, 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 it is expected that in combination with L452R there may be an increase in transmission and a reduction in antibody neutralization,” Pinsky said.
If the mutation makes the virus more resistant to antibodies, this could reduce the effectiveness of both vaccines and antibody treatments that have become a critical tool for doctors in the fight against Covid-19, according to Pinsky.
“I suspect existing vaccines will be a little less effective in preventing infection by this new variant,” he said, “but all vaccines are extremely effective in preventing hospitalizations and deaths.”
Eli Lilly’s bamlanivimab antibody treatment has been shown to be less effective in treating strains containing E484Q or L452R mutations. U.S. health regulators stopped distributing this antibody treatment last month, saying it was not as effective against the new variants.
The double mutant variant “has known mutations in the scariest place to have a mutation: the receptor-binding domain, where the virus is used to attach to cells in our body to enter,” he said Peter Chin-Hong, infectious disease expert. at the University of California at San Francisco. “Mutations are identical or strangely similar to mutations in variants that we already know and have been scientifically proven to be more transmissible and / or evade vaccines. Therefore, many believe that this Indian variant will also have these superpowers.”
Tom Kenyon, head of health at the HOPE Project and former director of global health at disease control and prevention centers, said scientists are finding more mutations, at least in part, because the new CDC director, Dr. Rochelle Walensky, led the agency to increase surveillance. “So the more we look for these, the more we will find them,” he said.
“There’s something about the‘ double ’of the world that scares people and makes it sound like it’s double,” 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 the UK variant B.1.1.7 which has become the predominant strain almost anywhere it goes, Chin- said. Hong.
“If the British variant went into a boxing ring with the Indian variant, the British variant will probably come out victorious. But only time will tell,” Chin-Hong said.
The longer it takes to vaccinate the world, the more chances the virus has of mutating into even worse strains, scientists say. Walensky, of the CDC, has warned of “imminent fatality” in the US as states roll back Covid-19 restrictions. He urged people to get vaccinated and continue to follow public health precautions, including masks and the practice of social distancing.
“The variants that scare me the most are the ones that haven’t been invented yet … the more the virus reproduces, the more we will see these escape mutants,” Chin-Hong said. “We need equity in global vaccination and continued battles against pandemic fatigue.”
California is scheduled to lift most Covid restrictions on June 15, but still plans to maintain a mask mandate.