A new, possibly "more transmissible" variant of COVID-19 that is specific to the United States, believed to be behind half of the country's coronavirus cases, has been reported by Illinois researchers.
In a study currently awaiting peer review, a team led by Southern Illinois University Carbondale researcher Keith Gagnon reported a new variant "specific to and dominant in the United States," which would mark the latest mutation discovery following those reported in the United Kingdom and South Africa. The discovery was submitted Monday to BioRxiv, a preprint server aimed at disseminating research while it undergoes peer review.
“It’s here. We found it,” Gagnon said in a statement. “It’s definitely home-grown and widespread, and we’re the first to characterize it.”
According to the Centers for Disease Control and Prevention, "multiple variants of the virus that causes COVID-19 have been documented in the United States and globally during this pandemic."
SIU researchers say their reported variant, called 20C-US, which has not yet been listed as an emerging variant by the CDC, has been traced as far back as May in Texas. Since then, it has mutated at least twice and is now most prevalent in the Upper Midwest.
They said they made their discovery "while looking at their own SARS-CoV-2 genome sequencing data from Illinois," according to a release.
“We predict that 20C-US may already be the most dominant variant of SARS-CoV-2 in the U.S.,” the article states.
Researchers wrote that the variant's emergence coincides with spikes in the country, which could mean it spreads more easily.
“There are hundreds of variants floating around, so for this one to rise to prominence suggests it might be more transmissible,” Gagnon said.
Similar to other variants of the virus, researchers believe the current coronavirus vaccines being administered in the U.S. could still be effective.
“Based on the mutations so far, I don’t think it will significantly impact the vaccine’s effectiveness," Gagnon said. "The catch is that the virus continues to evolve, and since May, it has acquired three mutations, and two of them are in the spike protein, one of which might affect antibody binding. There are a lot of unknowns.”
Currently, the CDC is closely following the emergence of two variants circulating in the United Kingdom and South Africa, but the agency says there is no current evidence to suggest the variants "cause more severe illness or increased risk of death." The U.K. variant has already been discovered in several countries around the world, including the U.S. and Canada.
Dr. Marielle Fricchione, medical director at the Chicago Department of Public Health, said health officials believe the strain causing problems in the U.K. is "likely circulating already" in the city.
"Other states have found that it's already circulating, it may have led to our second wave," Fricchione said. "That's purely speculation, but from what we learned from the first wave, and as we get more sequencing data from our local hospitals that have specimens, we'll be able to report a little bit more on that. But the general consensus from the CDC is that it's likely already circulating here."
Fricchione stressed that "layered mitigations" continue to be effective against the new strain.
"This isn't atypical for viruses, respiratory viruses, in particular," she said. "They mutate because they want to survive."
The Illinois Department of Public Health has also said it was monitoring the U.K. variant after the first known case in the United States was discovered in Colorado. Additional cases have also been reported in Indiana and Wisconsin.