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, California, November 19, 2020.
David Paul Morris | Bloomberg | Getty Images
Stanford University researchers have identified five new cases of a “double mutant” Covid-19 strain 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 attributed to a recent 55% increase in the number of cases in Maharashtra state, home to Mumbai, after months of declining cases.
It contains two major 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 is a fair amount of information about how these mutations behave in viruses alone, 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 some evidence that antibodies do not recognize that mutation 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 the coronavirus. It is too early to say whether the mutation makes the virus more contagious.
“But you would expect that in combination with the L452R, there could be an increase in transmission and a decrease in antibody neutralization,” Pinsky said.
If the mutation makes the virus more resistant to antibodies, it could reduce the effectiveness of both vaccines and antibody treatments, which Pinsky says have become a critical tool for doctors in the fight against Covid-19.
“I suspect that existing vaccines will be somewhat less effective at preventing infection from this new variant,” he said, “but all vaccines are extremely effective at preventing hospitalizations and deaths.”
Treatment with Eli Lilly bamlanivimab antibodies has been shown to be less effective in treating strains containing the E484Q or L452R mutations. US health regulators stopped distribution of that 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 clings to cells in our body to get in,” said Peter Chin-Hong, an infectious disease expert at the US. University of California San Francisco. “The mutations are either identical or eerily similar to mutations in variants we already know, scientifically proven to be more transmissible and / or evade vaccines. Therefore, many believe this Indian variant will also have these superpowers.”
Tom Kenyon, Chief Health Officer at Project HOPE and the former director of Global Health at the Centers for Disease Control and Prevention said scientists are finding more mutations, at least in part, because new CDC director Dr. supervision. “So the more we look for these, the more we will find them,” he said.
“There’s something about the ‘double’ world that scares people and it sounds like it’s doubly bad,” Kenyon said in an interview. “Any mutation that affects transmissibility or viral replication would be dangerous.”
It’s possible the new variety will remain in the Bay Area, unlike the UK’s B.1.1.7 variety, which has become the predominant species pretty much everywhere, Chin-Hong said.
“If the British variant goes into a boxing ring with the Indian variant, the British variant will likely come out victorious. But only time will tell,” said Chin-Hong.
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 “impending doom” in the US as states roll back Covid-19 restrictions. She has urged people to get vaccinated and continue to follow public health precautions, including wearing masks and practicing social distance.
“The variants that scare me the most are the ones that haven’t been invented yet … the more the virus replicates, we’ll keep seeing these escape mutants,” said Chin-Hong. “We need global vaccine equality and an ongoing fight against pandemic fatigue.”
California plans to lift most Covid restrictions on June 15, but still plans to maintain a mask mandate.