(Reuters) – The first study to analyze the structure of the new coronavirus from two waves of infection in a major city found that a more contagious strain dominates recent samples, researchers at Houston Methodist Hospital said on Wednesday.
They examined more than 5,000 virus genomes recovered from the first phase of the pandemic in Houston, an ethnically diverse city of 7 million people, and a more recent wave of ongoing infections.
The study, which has yet to be reviewed by outside experts, found that almost all of the second wave strains had a mutation, known as D614G, which increased the number of “spikes” on the virus. crown-shaped.
The spikes allow the virus to bind and infect cells, which increases the ability of the mutated virus to infect cells.
Researchers in Houston said patients infected with the variant strain had significantly higher amounts of the virus when initially diagnosed.
But they found little evidence that mutations in the virus made it more deadly, noting that the severity of COVID-19, the disease caused by the virus, was more strongly linked to the medical conditions and the underlying genetics of the patients.
They also said that certain regions of the spike protein – the primary target for coronavirus vaccines currently in development – have multiple mutations, possibly indicating that the virus is evolving in order to evade the body’s immune response.
Previous studies have shown that the coronavirus is mutating and evolving as it adapts to its human hosts.
Reporting by Deena Beasley; Editing by Tom Brown