At least four new variants of the coronavirus are keeping scientists awake at night.
One, first identified in southeast England, has now shown up in at least 50 countries and appears to be spreading more efficiently than older variations of the virus. Its appearance has frightened political leaders, who have closed borders and imposed travel restrictions in attempts to curb its spread.Others, identified in South Africa and Brazil, haven’t traveled as far and wide but show a constellation of mutations that have grabbed the attention of geneticists.And then there is a new variation that’s shown up in California that may or may not be driving renewed spread there.
“We don’t get much sleep, to be honest, lately,” said Dr. Christian Gaebler, a molecular immunologist at the Rockefeller University who is studying the body’s immune response to coronavirus infection.So far, none has done what scientists most fear and mutated to the point that it causes more severe disease, or evades the protection provided by vaccination. While some of the new variants appear to have changes that look like they could affect immune response, it’s only by a matter of degree.
At the top of the list for researchers in the US is the B.1.1.7 variant first seen in Britain. The US Centers for Disease Control and Prevention warned last week it could worsen the spread of the pandemic.
A variant first seen in South Africa called B.1.351 or 501Y.V2, has a different pattern of mutations that causes more physical alterations in the structure of the spike protein than B.1.1.7 does. One important mutation, called E484K, appears to affect the receptor binding domain — the part of the spike protein most important for attaching to cells.
P.1 and P.2
Two variants of concern have shown up first in Brazil. One, called P.1., has been found in 42% of specimens in one survey done in the Brazilian city of Manaus, and Japanese officials found the variant in four travelers from Brazil. “The emergence of this variant raises concerns of a potential increase in transmissibility or propensity for SARS-CoV-2 re-infection of individuals,” CDC said. P.1 also carries the E484K mutation.Original Source