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AHealth officials in the United States have announced a second and possibly a third person infected with a new, more transmissible strain of the SARS-CoV-2 virus, infectious disease experts are once again feeling a sense of déjà vu.
Just under a year ago, the early response to the coronavirus crisis was stifled by a failure to step up testing to detect the virus and stop its spread. Now, once again, it’s unclear how close the new strain, which first surfaced in the UK, could be in the US. Already a possible and probable case has been detected in Colorado and a case has been reported in California. But it is likely that the spread of the variant did not end there.
“It looks a lot like the period between January 19 or so when we had that first case in the Seattle area and six weeks later when all of a sudden it looks like we have community transmission in California and Seattle and who knows where else, ”said Michael Worobey, professor of evolutionary biology at the University of Arizona. “He has that feeling.”
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Trevor Bedford, a computer biologist at the Fred Hutchinson Cancer Research Institute, told STAT he doesn’t believe the new variant, called B.1.1.7, is still prevalent. There are 250 genetic sequences of SARS-2 virus from December cases in the United States that have been recorded in an international virus-sharing database known as GISAID; there is no B.1.1.7 among them, Bedford said. But he thinks it might just be a matter of time.
“The way I envisioned this job is… very similar to January, February,” he said. “There are seeding events that have happened all over the country. Some took, some didn’t.… And you can imagine that it should be more likely to be in places like New York and Boston with good travel connections to London, but it could have just happened to be picked up a little elsewhere.
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Worobey agreed that the new variant is probably already spreading in a number of parts of the country, traveling under the radar because the United States does not do enough sequencing of the SARS-2 viruses.
“We’re a little behind ball eight in terms of genomic sequencing, both in terms of absolute numbers and the sort of delay between sampling and output of the sequences, compared to the UK,” a declared Worobey. He warned that if the United States cannot find the cases and their spread is slow, they are likely to see the same type of rapid spread of the variant that the United Kingdom has seen.
The new variant has an unusual number of mutations, some of which appear to alter the behavior of the virus. It appears to be much more transmissible, increasing the rate at which infected people infect others.
There is no evidence to date that the variant triggers more severe disease. But hospitals strive to treat Covid patients as they are; more infections could lead to a higher death rate, due to lower quality of care.
“The death rate increases if health care systems are overwhelmed,” said Nahid Bhadelia, medical director of the Special Pathogens Unit at Boston Medical Center. “That’s how it works.”
Efforts are underway to try to figure out how far the new variant is spreading – one of them led by Worobey’s lab. His team is trying to develop a test that could be used to test for variants of the virus in wastewater from community sewer systems. If the test works, he said, the lab will ship test material to other labs, test samples in its own lab, or share the recipe for making the primers and probes for the test to be widely used. .
“I think sewage will be the best, very short term, way to get better management rather than waiting for some weird lab like Colorado to encounter one of these in an individual patient sample,” said Worobey.
The Centers for Disease Control and Prevention is also stepping up efforts to increase sequencing of SARS-2 viruses, officials said Wednesday.
Gregory Armstrong, who leads the CDC’s team monitoring virus variants, said the national SARS-CoV-2 strain surveillance system, which launched in November, is expanding to process 750 samples submitted by Reports for sequencing and study every week. . The CDC is also working with national reference laboratories around the country, providing funding for the sequencing of several times the virus. The hope is to get to around 3,500 per week, Armstrong noted.
He said experts at the CDC and elsewhere do not believe the mutations in B.1.1.7 will seriously undermine the protection generated by Covid vaccines in use or in production. “It may have a small impact. But keep in mind that it is likely that the amount of immunity induced by natural infection or by vaccination is high enough that a slight decrease [antibody] the title may not have a noticeable effect at all, ”Armstrong said.
But Bedford said the increased use of the vaccine will put additional pressure on the SARS-2 viruses to mutate to try to evade the protection triggered by the vaccine.
“It’s even more of an argument to try to get herd immunity faster and reduce transmission through vaccination,” he said. “The sooner we can get enough people vaccinated, the better we will prevent this variant and other future mutants from spreading.”
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