Submission + - Why Scientists Are Very Worried About the Variant From Brazil (npr.org)
An anonymous reader writes: New coronavirus variants seem to be cropping up everywhere. There's one from the U.K., which is more contagious and already circulating in the United States. There's one from South Africa, which is forcing Moderna and Pfizer to reformulate their COVID-19 vaccines and create "booster" shots, just to make sure the vaccines maintain their efficacies. But for some scientists, the most worrying variant might be the newest one. A variant called P.1, which emerged in early December in Manaus, Brazil, and by mid-January had already caused a massive resurgence in cases across the city of 2 million people. [...] The concern with P.1 is twofold: scientists don't understand why the variant has spread so explosively in Brazil, and the variant carries a particularly dangerous set of mutations.
While the variant from the U.K. took about three months to dominate the outbreak in England, P.1 took only about a month to dominate the outbreak in Manaus. In addition, Manaus had already been hit extremely hard by the virus back in April. One study estimated that the population should have reached herd immunity and the virus shouldn't be able to spread easily in the community. So why would the city see an even bigger surge 10 months later? Could P.1 be evading the antibodies made against the previous version of the virus, making reinfections easier? Could it just be significantly more contagious? Could both be true? "While we don't *know* exactly why this variant has been so apparently successful in Brazil, none of the explanations on the table are good," epidemiologist Bill Hanage, at Harvard University, wrote on Twitter.
Reinfections are a serious concern for several reasons. First off, like the variant from South Africa, P.1 carries a cluster of mutations along the surface of the virus where antibodies — especially the potent antibodies — like to bind. "They are kind of the major targets of the immune system," says virologist Penny Moore at the National Institute for Communicable Diseases in South Africa and the University of KwaZulu-Natal. "So when we see a whole lot of mutations in [those surfaces], it raises the possibility that the mutations might be conferring immune escape." That is, the mutations are helping the virus evade antibodies or escape recognition by them. In essence, the mutations are providing the virus with a type of invisibility cloak. And thus, now we have a game of "cat and mouse," says virologist Ravi Gupta, between the virus and the vaccine. The virus finds ways around the vaccine (and our immune system), says Gupta, and so the manufacturers have to reformulate the vaccines (or else we run the risk of getting infected twice).
While the variant from the U.K. took about three months to dominate the outbreak in England, P.1 took only about a month to dominate the outbreak in Manaus. In addition, Manaus had already been hit extremely hard by the virus back in April. One study estimated that the population should have reached herd immunity and the virus shouldn't be able to spread easily in the community. So why would the city see an even bigger surge 10 months later? Could P.1 be evading the antibodies made against the previous version of the virus, making reinfections easier? Could it just be significantly more contagious? Could both be true? "While we don't *know* exactly why this variant has been so apparently successful in Brazil, none of the explanations on the table are good," epidemiologist Bill Hanage, at Harvard University, wrote on Twitter.
Reinfections are a serious concern for several reasons. First off, like the variant from South Africa, P.1 carries a cluster of mutations along the surface of the virus where antibodies — especially the potent antibodies — like to bind. "They are kind of the major targets of the immune system," says virologist Penny Moore at the National Institute for Communicable Diseases in South Africa and the University of KwaZulu-Natal. "So when we see a whole lot of mutations in [those surfaces], it raises the possibility that the mutations might be conferring immune escape." That is, the mutations are helping the virus evade antibodies or escape recognition by them. In essence, the mutations are providing the virus with a type of invisibility cloak. And thus, now we have a game of "cat and mouse," says virologist Ravi Gupta, between the virus and the vaccine. The virus finds ways around the vaccine (and our immune system), says Gupta, and so the manufacturers have to reformulate the vaccines (or else we run the risk of getting infected twice).
