Scientists in Oregon have discovered a homemade version of a rapidly spreading coronavirus variant that first appeared in Britain – but is now combined with a mutation that could make the variant less susceptible to vaccines.
Researchers have so far found only a single case of this formidable combination, but genetic analysis has suggested that the variant was acquired in the community and did not appear in the patient.
“We don’t import it from anywhere else in the world – it happened spontaneously,” said Brian O’Roak, a geneticist at Oregon Health and Science University who led the work. He and his colleagues participate in the Center for Disease Control and Prevention’s effort to track down variants and deposit their results in databases shared by scientists.
Sign up for the New York Times newsletter The Morning
The variant originally identified in Britain, called B.1.1.7, has spread rapidly across the United States and is responsible for at least 2,500 cases in 46 states. This form of the virus is more contagious and deadly than the original version, and is expected to be responsible for most infections in the United States in a few weeks.
The new version that appeared in Oregon has the same backbone, but also a mutation – E484K, or “Eek” – seen in variants of the virus that circulate in South Africa, Brazil and New York.
Laboratory studies and clinical trials in South Africa indicate that the Eek mutation makes current vaccines less effective in dulling the body’s immune response. (The vaccines still work, but the findings are worrying enough that Pfizer-BioNTech and Moderna have started testing new versions of their vaccines designed to defeat the variant found in South Africa.)
Variant B.1.1.7 with Eek also emerged in Great Britain, designated by scientists as a “concern variant”. But the virus identified in Oregon appears to have evolved independently, said O’Roak.
O’Roak and his colleagues found the variant among the coronavirus samples collected by the Oregon State Public Health Laboratory across the state, including some from an outbreak in a healthcare setting. Of the 13 test results they analyzed, 10 ended up being B.1.1.7 alone and one the combination.
Other experts said the discovery was not surprising, because the Eek mutation emerged in forms of the virus around the world. But the occurrence of the mutation in B.1.1.7 is worth watching, they said.
In Britain, this version of the variant accounts for a small number of cases. But when the combination developed there, B.1.1.7 had already spread across the country.
“We are at the point where B.1.1.7 is just being introduced” in the United States, said Stacia Wyman, a specialist in computational genomics at the University of California, Berkeley. “As it evolves and the dominant thing slowly becomes, more mutations can accumulate.”
Viral mutations can increase or weaken each other. For example, the variants identified in South Africa and Brazil contain many of the same mutations, including Eek. But the Brazilian version has a mutation, K417N, which is not present in the South African version.
In a study published on Thursday in Nature, the researchers compared the antibody responses to all three worrying variants – those identified in Britain, South Africa and Brazil. Consistent with other studies, they found that the variant that hit South Africa is more resistant to antibodies produced by the immune system.
But the variant that circulated in Brazil was not as resistant, although it carried the Eek mutation. “If you have the second mutation, you don’t see such a bad effect,” said Michael Diamond, a viral immunologist at the University of Washington in St. Louis, who led the study.
It is too early to say whether the Oregon variant will behave like those in South Africa or Brazil. But the idea that other mutations could weaken Eek’s effect is “excellent news,” said Wyman.
Overall, she said, the Oregon discovery reinforces the need for people to continue to take precautions, including wearing a mask, until a substantial portion of the population is immunized.
“People don’t have to go crazy, but they need to remain vigilant,” she said. “We can’t let our guard down yet as long as there are these more communicable variants in circulation.”
This article was originally published in The New York Times.
© 2021 The New York Times Company