Viral Variation
UNM Scientists Detect New SARS-CoV-2 Mutation in New Mexico
Scientists have found SARS-CoV-2 to be a wily adversary since it was first identified in China a little over a year ago, with the novel coronavirus demonstrating a stubborn ability to mutate as it tries to evade the human immune system.
A pair of University of New Mexico scientists has found evidence that a new viral variant, termed Q677P, has emerged in New Mexico and nearby Western states over the past few months – while an identical mutation appeared in samples taken in Louisiana.
In a paper posted this week on medRxiv, the online preprint server for health sciences, Darrell Dinwiddie, PhD, assistant professor in the Department of Pediatrics, and Daryl Domman, PhD, assistant professor in the Center for Global Health, report that the mutations were found on the “spike” protein, a distinctive feature that plays a key role in helping the virus to gain access to host cells. The pair were joined in the study by colleagues at UNM and co-authors in Louisiana, New York, Pennsylvania, Wyoming and Switzerland.
It is unclear at this point whether the newly identified variation in the virus’s genome increases its transmissibility. “This is something we need to keep an eye on to figure out if that is the case,” Domman says.
The new findings underline the importance of ongoing genomic surveillance to see how the virus is altering itself. Without it, Domman says, “we’re a little bit flying blind in terms of understanding how the virus is responding to our control measures.”
They’re also a sobering reminder of what scientists are up against, Domman says. “It underscores the fact that as we have higher case counts, locally, regionally and nationally, every single one of those new cases is a new opportunity for the virus to explore and have a mutation and be a little bit better than the last time around.”
As they reproduce inside a host cell, viruses constantly alter small portions of their genome as a defense against the antibodies the immune system creates to neutralize them – annual variations in the influenza virus are one well-known example. In the coronavirus, these new mutations pose challenges to crafting an effective vaccine.
Mutations have been found at similar locations on the COVID spike protein in other parts of the world, Dinwiddie says, adding, “It’s not a surprise that the spike is where many of these variants occur.”
For much of the past year, Dinwiddie and Domman have been sequencing, depositing and monitoring SARS-CoV-2 genomes logged into GISAID, an international database that provides open access to nearly 500,000 coronavirus genomes gathered from around the world.
They have found that 11.3 percent of the genomes collected from New Mexico between December 2020 and January 2021 reflect the new variant. It is not unique to the state, however, and has also been seen in Colorado, Wyoming and Texas. Additional mutations at the same position in the spike protein are being found around the world and appear to have occurred independently – a case, they say, of what is known as convergent evolution.
While the jury is out on whether the new variants increase the transmissibility of the coronavirus, there is concern that mutations in the spike protein could lessen the effectiveness of newly introduced vaccines, Dinwiddie says.
“Vaccines are designed not to just attack a single place in a protein,” he says, but “the evidence is that we’re seeing reduced protection against some of these spike changes with some of these vaccines.”
The good news is that the innovative messenger RNA technology that was employed to rapidly develop the vaccines also enables drug manufacturers to tweak them to recognize and defend against new viral strains, he says.
Domman notes, “Our greatest tool to making sure our vaccines stay effective is keeping cases counts down.” And in the end that translates into the same old standbys: wearing masks, thorough handwashing and maintaining physical distance.
