A recent study sparked some worry last week when it revealed a mutation “of urgent concern” in the virus responsible for COVID-19. But experts say more research is needed to determine what that really means.
The preliminary, non peer-reviewed study from the Los Alamos National Laboratory in New Mexico indicated that a COVID-19 strand containing a specific mutation — on the spike protein D614G — is emerging as the dominant form of the virus.
The U.S. team’s study, which analyzed data from coronavirus patients in England, also suggested the mutation could be making the virus more infectious.
The problem, experts say, is that the research doesn’t reveal any proof of that.
“There’s really no evidence from the scientific study that this particular mutation is causing the virus to be more transmissible than other genetic variants of the virus,” said Dr. Isaac Bogoch, an infectious diseases specialist based at Toronto General Hospital and a faculty member at the University of Toronto.
“Could a mutation (with that effect) happen? Sure. Will it happen? Who knows.”
Mutations are commonplace in nature, whether it’s in viruses or any other living organism, and they occur when a “mistake” is made during a cell’s replication phase.
While some mutations can make a virus more potent, others might make it less effective. And most just don’t do anything.
“Viruses mutate, that’s what they do, they just change over time,” said BC Children’s Hospital clinical researcher Dr. Srinivas Murthy, who added he’s not concerned with the findings from the U.S. research.
“Truthfully, I have no takeaways from it. … We have no data from this (study) that says the transmissibility is different and we have no data from this that says the severity is any different.”
Scientists have found plenty of mutations to the novel coronavirus, not just D614G. A recent study from University College London indicated that ”198 sites in the SARS-CoV-2 genome appear to have already undergone recurrent, independent mutations.”
That study also found the vast majority of those mutations to be ”likely neutral.”
Art Poon, an associate health sciences professor and expert in virus evolution at Western University in London, Ont., says people generally fear mutations because they perceive the word to mean a freakish flaw.
“When people hear mutation they think of X-Men, right?” Poon said. “But it’s important to remember most mutations don’t do much of anything.”
Poon says the reason D614G has been given so much attention is because its of prevalence in the COVID-19 genome.
Scientists believe the mutation was introduced to Europe in early February, with Poon adding it was likely ”inherited from a single ancestor that happened to be one of the first lineages to move out of China.”
That would mean the specific D614G mutation isn’t technically new, as most cases in the U.S. and Canada would have probably come from this strand.
Even if Canada’s first COVID-19 cases came from the original virus that didn’t carry the D614G mutation, Poon said North America would soon after have had an influx in cases that did carry the mutation once the virus migrated in from Europe.
That could explain why the strand is emerging as dominant, as the U.S. study suggested, he said.
“But that’s not because of selection for human-to-human transmission, it would be due to what we call a ‘founder effect’ — (where) the lineage founding the epidemic in Europe happened to carry this mutation,” Poon said.
Bogoch said mutations can actually help us better understand a virus by pinpointing its origin.
“They’re like fingerprints of the virus,” he said. ”And there’s a lot of good information that these mutations can really help scientists with.”
While mutations can potentially become problematic in terms of vaccine development, experts say there’s no evidence D614G will cause researchers to have to abandon any work that’s already being done.
And those problems can usually be solved, anyway.
Vaccines are created to target a specific part of the virus, Bogoch said, so if the part being targeted is changing, the vaccine would also need to adapt. Usually that means creating a vaccine that is constantly updated and taken periodically — similar to the flu shot — rather than a one-time inoculation.
“That’s why we have seasonal influenza vaccine, because we’re essentially playing an arms race with how we create a vaccine against an evolving virus,” Bogoch said. “So could that happen with COVID-19? Maybe, who knows. It is certainly a possibility.
“But it’s just too soon to speculate how this is going to impact a vaccine that we don’t even have yet.”
Melissa Couto, The Canadian Press
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