The race against the virus that causes COVID-19 has taken a new turn: mutations appear quickly and the longer it takes to vaccinate people, the more likely it is that a variant that can escape current tests, treatments and vaccines could emerge.
The coronavirus is becoming more and more genetically diverse, and health officials say the high rate of new cases is the main reason.
Each new infection gives the virus a chance to mutate as it copies itself, threatening to reverse the progress made so far in controlling the pandemic.
The World Health Organization (WHO) on Friday called for more efforts to detect new variants.
The US Centers for Disease Control and Prevention (CDC) said a new version, first identified in the UK, could become dominant in the US by March.
While it doesn’t lead to more serious illness, it will lead to more hospitalizations and deaths just because it spreads much more easily, he said, warning of “a new phase of growth. exponential ”.
So far, vaccines appear to remain effective, but there are signs that some of the new mutations could interfere with tests for the virus and reduce the effectiveness of antibody drugs as treatments.
“We are in a race against time” because the virus “can run into a mutation” that makes it more dangerous, said Dr. Pardis Sabeti, an evolutionary biologist at the Broad Institute at MIT and Harvard.
Younger people may be less willing to wear masks, avoid crowds, and take other steps to avoid infection because the current strain doesn’t seem to make them very sick, but “in a mutational change, it could “, warned Sabeti who documented a change in the Ebola virus during the 2014 epidemic which made the situation worse.
Mutations on the rise
It is normal for viruses to acquire small changes or mutations in their genetic makeup as they reproduce.
Those that help the virus to flourish give it a competitive edge and thus crowd out other versions.
In March 2020, a mutation called D614G appeared, which made it more likely to spread. It quickly became the dominant version in the world.
Now, after months of relative calm, “we have started to see a striking evolution” of the virus, wrote biologist Trevor Bedford of the Fred Hutchinson Cancer Research Center in Seattle on Twitter last week.
“The fact that we’ve observed three variants of concern emerging since September suggests that there are likely more to come,” he said.
The one identified in the UK has now been reported in at least 30 countries, including the United States.
Soon after, South Africa and Brazil reported new variants.
Current vaccines induce immune responses broad enough to remain effective, say many scientists.
Sufficient genetic change may eventually require fine-tuning the vaccine formula, but “it will probably take years if we use the vaccine well rather than months,” said Dr. Andrew Pavia of the University of Utah.
Health officials are also worried if the virus changes enough, people could contract COVID-19 a second time. Reinfection is currently rare, but Brazil has already confirmed a case in a person with a new variant who had been sickened by a previous version several months earlier.
What to do
“We see a lot of variants, of viral diversity, because there are a lot of viruses out there,” and reducing new infections is the best way to fight that, said Dr. Adam Lauring, an infectious disease expert at the University of Michigan at Ann Tonnelle.
Loyce Pace, who heads the nonprofit World Health Council and is a member of Joe Biden’s COVID-19 advisory board, said the same precautions scientists advised from the start “still work and they still count” .
“We always want people to hide,” she says. “We still need people to limit gatherings with people outside their homes. We still need people to wash their hands and be really vigilant about these public health practices, especially as these variants emerge.