Scientists say they have identified a new variant of SARS-CoV-2 – the virus that causes COVID-19 – in the United States, which may be the most dominant form in the country.
The variant – known as 20C-US – appears to have taken root in the southern part of the country in late spring and early summer 2020, with researchers tracking its first appearance in Texas in May, according to a study presented in pre-print server bioRxiv.
The article is a preliminary report that has not yet been peer-reviewed and, therefore, should not be considered conclusive. But scientists at Southern Illinois University (SIU) wrote in the study that the variant “probably … became the most dominant variant in the US”
“It’s here. We found it,” Keith Gagnon, an author of the study of SIUfrom the School of Medicine, said in a statement. “It is definitely homemade and widespread, and we are the first to characterize it.”
The variant does not appear to have spread far beyond the United States, although it has also been detected at very low levels in a handful of other countries, including Mexico, Australia, New Zealand, Singapore, Thailand, Taiwan, Poland and Israel, the researchers said.
Within the United States, it appears to be more prevalent in the Upper Midwest, the team concluded in its analysis, noting that the 20C-US is expected to continue to spread across the country.
Scientists have not yet determined whether or not the variant is more transmissible than others. But Gagnon and his team says the rise of the 20C-US coincides with the second and third wave of COVID infections in the USA – circumstantial evidence that it may be more infectious than other variants.
“There are hundreds of variants floating around, so the fact that it stands out suggests that it can be more transmissible,” Gagnon said.
The increase in the variant also coincides with substantially reduced lethality rates in the United States, despite the recent increase in cases. Although many factors contribute to the lethality rates, the scientists say in the study that it is “plausible that 20C-US represents a SARS-CoV-2 variant with superior Transmissibility but a milder illness. “
“These variants can generate an aptitude advantage for the virus, as they are more likely to spread silently,” wrote the authors.
Like SARS-CoV-2 has spread throughout the world, the virus has undergone genetic mutations that led to the emergence of several new variants. New mutations are not always beneficial for the virus, but in some cases they alter their characteristics in noticeable ways.
New variants recently detected in the United Kingdom and South Africa, for example, appear to be more transmissible than the original.
Daniel Davis, professor of immunology at the University of Manchester, UK, who was not involved in the research, said Newsweek: “As more and more samples of this virus are analyzed genetically, we are understanding a lot more about how the virus varies around the world. The variation is expected and not alarming in itself. It is well established that different versions of viruses emerge and fall over time. “
“This new variant, dubbed 20C-US, is now known to be one of the common versions of the virus present in the United States, but there are still many other versions of the virus circulating in the United States”
It is also unclear whether the genetic changes present in the new US variant will affect the effectiveness of COVID-19 vaccines, Although Gagnon said that there is not likely to be a big impact for now.
“Based on the mutations so far, I don’t think it will significantly affect the vaccine’s effectiveness. The problem is that the virus continues to evolve and, since May, has acquired three mutations, two of which are in the peak protein, one of which can affect the binding of the antibody. There are many unknowns. “
The spike protein, located on the outside of the virus, allows it to bind and enter human cells.
Ian Jones, professor of virology at the University of Reading in the UK, said Newsweek currently, there is no reason to suggest that the vaccine will not be effective against the new variant or that it will cause more serious illnesses.
“This is yet another example of COVID viruses adapting to the human population, “he said.” Changes are expected to increase transmission, as they would be selected naturally as the epidemic spreads. In this case, the suggested key mutation may not alter the virus’s binding to the cell, but the entry step that immediately follows it, equally effective in increasing transmission. “
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