A large genetic study of SARS-CoV-2 indicates viruses with a particular gene variant are outspreading others, the Washington Post reports.
Researchers led by Houston Methodist Hospital's James Musser sequenced the genomes of more than 5,000 SARS-CoV-2 samples obtained during two COVID-19 waves in Houston. As they report in an as-yet-to-be peer-reviewed pre-print at MedRxiv, the researchers found the viruses with a Gly614 amino acid replacement in the spike protein increased over time and caused nearly all of the COVID-19 cases in the second wave. They further noted that patients infected with viruses with this variant had higher nasopharyngeal viral loads at diagnosis.
The findings suggested to the researchers that the alteration may enable SARS-CoV-2 to spread more easily.
David Morens from the National Institute of Allergy and Infectious Diseases tells the Post that while the results suggest the virus has become more transmissible, he also cautions that this is just one study and "you don't want to over-interpret what this means." Scripps Research Institute's Kristian Andersen, though, tells the Post the preprint "just confirms what has already been described — G increased in frequency over time."
Morens adds that while they sequenced a large number of viral samples, he and his colleagues only captured about 10 percent of the known cases in Houston and that more sequencing needs to be done across the US to monitor SARS-CoV-2.