The race against the virus that causes COVID-19 has taken a new turn: Mutations are rapidly popping up and the longer it takes to vaccinate people, the more likely it is that a variant that can elude current tests, treatments and vaccines could emerge.
The coronavirus is becoming 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 makes copies of itself, threatening to undo the progress made so far to control the pandemic.
On Friday, the World Health Organization (WHO) urged more effort to detect new variants.
The US Centers for Disease Control and Prevention (CDC) said a new version, first identified in the United Kingdom, may become dominant in the United States by March.
Although it does not cause more severe illness, it will lead to more hospitalisations and deaths just because it spreads much more easily, it said, warning of “a new phase of exponential growth”.
So far, vaccines seem to remain effective, but there are signs some of the new mutations may undermine tests for the virus and reduce the effectiveness of antibody drugs as treatments.
“We’re in a race against time” because the virus “may stumble upon a mutation” that makes it more dangerous, said Dr Pardis Sabeti, an evolutionary biologist at the Broad Institute of MIT and Harvard.
Younger people may be less willing to wear masks, shun crowds and take other steps to avoid infection because the current strain does not seem to make them very sick, but “in one mutational change, it might”, warned Sabeti who documented a change in the Ebola virus during the 2014 outbreak that made it much worse.
It is normal for viruses to acquire small changes or mutations in their genetic alphabet as they reproduce.
Ones that help the virus flourish give it a competitive advantage and thus crowd out other versions.
In March 2020, a mutation called D614G emerged that made it more likely to spread. It soon became the dominant version in the world.
Now, after months of relative calm, “we’ve started to see some striking evolution” of the virus, biologist Trevor Bedford of the Fred Hutchinson Cancer Research Center in Seattle wrote on Twitter last week.
“The fact that we’ve observed three variants of concern emerge 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 US.
Soon afterwards, South Africa and Brazil reported new variants.
Current vaccines induce broad enough immune responses that they should remain effective, many scientists say.
Enough genetic change eventually may require tweaking the vaccine formula but “it’s probably going to be on the order of years if we use the vaccine well rather than months”, Dr Andrew Pavia of the University of Utah said.
Health officials also worry if the virus changes enough, people might get COVID-19 a second time. Reinfection currently is rare, but Brazil already confirmed a case in someone with a new variant who had been sickened with a previous version several months earlier.
“We’re seeing a lot of variants, viral diversity, because there’s a lot of virus out there” and reducing new infections is the best way to curb it, said Dr Adam Lauring, an infectious diseases expert at the University of Michigan in Ann Arbor.
Loyce Pace, who heads the nonprofit Global Health Council and is a member of Joe Biden’s COVID-19 advisory board, said the same precautions scientists have been advising all along “still work and they still matter”.
“We still want people to be masking up,” she said. “We still need people to limit congregating with people outside their household. We still need people to be washing their hands and really being vigilant about those public health practices, especially as these variants emerge.”