Study shows coronavirus mutating
Researchers speculate if virus has evolved to be more contagious
Scientists in Houston on Wednesday released a study of more than 5,000 genetic sequences of the coronavirus, which reveals the virus’s continual accumulation of mutations, one of which may have made it more contagious.
That mutation is associated with a higher viral load among patients upon initial diagnosis, the researchers found.
The study, which has not been peer-reviewed, was posted Wednesday on the preprint server MedRxiv. It appears to be the largest single aggregation of genetic sequences of the virus in the United States. A larger batch of sequences was published this month by scientists in the United Kingdom, and like the Houston study, concluded that a mutation that changes the structure of the “spike protein” on the surface of the virus may be driving the outsize spread of that strain.
The new report did not find that these mutations have made the virus deadlier. All viruses accumulate genetic mutations, and most are insignificant, scientists say. Coronaviruses such as SARS-CoV-2, which causes the illness COVID-19, are relatively stable as viruses go, because they have a proofreading mechanism as they replicate.
But every mutation is a roll of the dice, and with transmission so widespread in the United States — which continues to see tens of thousands of new confirmed infections daily — the virus has had abundant opportunities to change, potentially with troublesome consequences, said study author James Musser of Houston Methodist Hospital.
“We have given this virus a lot of chances,” Musser told the Washington Post. “There is a huge population size out there right now.”
Scientists from Weill Cornell Medicine, the University of Chicago, Argonne National Laboratory and the University of Texas at Austin also contributed to the study.
David Morens, virologist at the National Institute of Allergy and Infectious Diseases and senior adviser to Anthony Fauci, reviewed the study and said the findings point to the likelihood that the virus has become more transmissible and that this may affect for our ability to control it.
“Wearing masks, washing our hands, all those things are barriers to transmissibility, or contagion, but as the virus becomes more contagious it statistically is better at getting around those barriers,” said Morens.
Mutation also has implications for the formulation of vaccines, he said. “Although we don’t know yet, it is well within the realm of possibility that this coronavirus, when our population-level immunity gets high enough, this coronavirus will find a way to get around our immunity,” Morens said. “If that happened, we’d be in the same situation as with flu. We’ll have to chase the virus and, as it mutates, we’ll have to tinker with our vaccine.”