A medical worker wearing personal protective equipment (PPE) inserts a Covid-19 test tube into a box at a drive-thru test site at the Alemany Farmers Market in San Francisco, Calif., November 19, 2020.
David Paul Morris | Bloomberg | Getty Images
Researchers at Stanford University have identified five new cases of a recently discovered “double mutant” Covid-19 strain in the San Francisco Bay Area. Doctors suspect it could be more contagious and resist existing vaccines.
The new variant originated in India, where it is credited with a recent 55% increase in cases in Maharashtra state, where Mumbai is located, after months of declining cases.
It contains two key mutations, which scientists refer to as 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 Lab, who has discovered the new variant in the United States
“There is a decent amount of information on how these mutations behave in viruses alone, but not in combination,” Pinsky said in an interview.
In other variations, the L452R mutation has been shown to make the virus more transmissible. There is also some 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 sensitive to neutralizing antibodies, which help fight the coronavirus. It is still too early to tell if the mutation makes the virus more contagious.
“But you would expect that in combination with L452R there could be an increase in transmission as well as a reduction in neutralization of antibodies,” Pinsky said.
If the mutation makes the virus more resistant to antibodies, it could reduce the effectiveness of vaccines as well as antibody treatments that have become an essential tool for doctors in the fight against Covid-19, according to Pinsky.
“I suspect that the existing vaccines will be slightly less effective at preventing infection with this new variant,” he said, “but all vaccines are extremely effective at preventing hospitalizations and death.”
Eli Lilly’s bamlanivimab antibody therapy was less effective in treating strains containing the E484Q or L452R mutations. U.S. health regulators halted distribution of this antibody therapy last month, saying it was not so effective against the newer variants.
The double mutant variant “has known mutations in the scariest place to have a mutation – the receptor binding domain, which the virus uses to latch onto cells in our bodies in order to enter,” said Peter Chin-Hong, an expert in infectious diseases. at the University of California at San Francisco. “The mutations are either the same or strangely similar to mutations in variants that we already know that have been shown to be scientifically more transmissible and / or elude vaccines. Therefore, many believe that this Indian variant will also have these superpowers.”
Tom Kenyon, director of health at Project HOPE and former director of global health for the Centers for Disease Control and Prevention, said scientists were finding more mutations, at least in part, because CDC’s new director Dr Rochelle Walensky, ordered the agency to increase surveillance. “So the more we look for these, the more we are going to find them,” he said.
“There is something about the global ‘double’ that scares people and makes it seem like a bad double,” Kenyon said in an interview. “Any mutation affecting viral transmissibility or replication would be dangerous.”
There’s a chance the new variant will stay in the Bay Area, unlike the UK’s B.1.1.7 variant which has become the predominant strain pretty much wherever it goes, Chin-Hong said.
“If the British variant entered a boxing ring with the Indian variant, the British variant will likely emerge victorious. But only time will tell,” Chin-Hong said.
The longer it takes to vaccinate the world, the more likely the virus is to mutate into even worse strains, scientists say. Walensky of the CDC has warned of “looming catastrophe” in the United States as states roll back Covid-19 restrictions. She urged people to get vaccinated and to continue to follow public health precautions, including wearing masks and practicing social distancing.
“The variants that scare me the most are the ones that haven’t been invented yet … the more the virus replicates, we will continue to see these mutants escape,” Chin-Hong said. “We need global equity in immunization and continued battles against pandemic fatigue.”
California is set to lift most Covid restrictions by June 15, but still plans to keep a mask mandate in place.