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 while making copies of itself, threatening to undo the progress made so far in controlling the pandemic.
The US Centers for Disease Control (CDC) said that a new version first identified in the UK may become dominant in the US in March.
Although it does not cause more serious disease, it will lead to more hospitalizations and deaths simply because it spreads much more easily, the CDC said, warning of “a new phase of exponential growth.”
“We need to do everything we can now … to get the transmission as low as possible,” said Dr. Michael Mina of Harvard University.
“The best way to prevent the emergence of mutant strains is to slow down transmission.”
So far, vaccines appear to remain effective, but there are indications that some of the new mutations may undermine evidence for the virus and reduce the effectiveness of antibody drugs as treatments.
“We’re in a race against time” because the virus “can stumble upon a mutation” that makes it more dangerous, said Dr. Pardis Sabeti, an evolutionary biologist at the Broad Institute of MIT and Harvard.
Dr. Sabeti documented a change in the Ebola virus during the 2014 outbreak that made it much worse.
It is normal for viruses to make small changes or mutations in their genetic alphabet as they reproduce. Those that help the virus to thrive give it a competitive advantage and therefore displace other versions.
Now, after months of relative calm, “we have started to see an amazing evolution” of the virus, biologist Trevor Bedford of the Fred Hutchinson Cancer Research Center in Seattle said via Twitter.
“The fact that we have seen three lines of concern emerging since September suggests that there are likely more to come.”
Soon after, South Africa and Brazil reported new variants, and the main mutation in the version identified in Britain appeared in a different version “that has been circulating in Ohio … at least since September,” said Dr. Dan Jones, a Ohio State University pathologist, who announced that finding last week.
“The important finding here is that this is unlikely to be travel related” and instead may reflect that the virus acquires similar mutations independently as more infections occur, Dr. Jones said.
That also suggests that travel restrictions could be ineffective, Dr. Mina said.
Because the United States has so many cases, “we can generate our own variants that are as bad or worse” as those in other countries, he said.
Treatment, vaccine, risks of reinfection.
Some laboratory tests suggest that the variants identified in South Africa and Brazil may be less susceptible to antibody drugs or convalescent plasma, the antibody-rich blood of COVID-19 survivors, both of which help people fight the virus. .
US government scientists are “actively investigating” that possibility, said Dr. Janet Woodcock of the US Food and Drug Administration.
The (US) government is encouraging the development of multiple antibody treatments instead of single antibody drugs to have more ways to attack the virus should one prove ineffective, he said.
Current vaccines induce immune responses broad enough to remain effective, many scientists say.
Sufficient genetic change may eventually require adjusting the vaccine formula, but “it will probably be on the order of years if we use the vaccine well rather than months,” Dr. Andrew Pavia of the University of Utah told the Infectious Diseases Society. from America.
Health officials are also concerned that if the virus changes enough, people could contract COVID-19 a second time.
Currently, reinfection is rare, but Brazil has already confirmed a case in someone with a new variant who had fallen ill with an earlier version several months earlier.
“We’re seeing a lot of variant, viral diversity, because there are a lot of viruses out there,” and reducing new infections is the best way to stop it, said Dr. Adam Lauring, an infectious disease expert at the University of Michigan. .
Loyce Pace, who heads the nonprofit Global Health Council and is a member of President-elect Joe Biden’s COVID-19 advisory board, said that the same precautions scientists have been advising all along “still work and still are important”.
“We still want people to be masking themselves,” he said Thursday in a webcast presented by the Johns Hopkins Bloomberg School of Public Health.
“We still need people to just congregate with people outside their home.
“We still need people to wash their hands and be really vigilant about those public health practices, especially as these variants emerge.”