The emergence of new variants of the virus that causes Covid-19—including one in the U.K. that British officials say could be more deadly than earlier versions—signals a future in which health authorities are locked in a cat-and-mouse battle with a shape-shifting pathogen.
Faster-spreading coronavirus strains that researchers fear could also make people sicker or render vaccines less effective threaten to extend lockdowns and lead to more hospitalizations and deaths, epidemiologists caution. But, they said, it doesn’t mean the contagion can’t be contained.
“We’re living in a world where coronavirus is so prevalent and rapidly mutating that there are going to be new variants that pop up,” Anthony Harnden, a physician who advises the U.K. government, told Sky News. “We may well be in a situation where we end up having to have an annual coronavirus vaccine” to cope with emerging strains.
As the new variant in the U.K. has spread across the country, hospitals have been under more strain than they were in the first wave of the pandemic in the spring, and the national Covid-19 death toll is expected to surpass 100,000 in coming days. But in the week ended Sunday, new daily cases were down 22% from the previous seven days.
Matt Hancock, the U.K.’s health secretary, said that was because of national restrictions in place since the start of the year. But in a television interview, Mr. Hancock warned, “We are a long, long, long way” before cases would be low enough for restrictions to be lifted.
The U.K. variant is one of several that have emerged in recent months to cause concern among researchers. Others have emerged in South Africa and Brazil.
Anthony Fauci, President Biden’s chief medical adviser for the Covid-19 pandemic, said on CBS on Sunday that U.S. authorities need to expand genomic surveillance to identify variants of the virus.
Dr. Fauci said current vaccines remain effective. “What we will do and are doing already is making preparations for the possibility that down the pipe, down the line, we may need to modify and upgrade the vaccines. We don’t need to do that right now,” he said. “The best way to prevent the further evolution of these mutants is to vaccinate as many people as possible with the vaccines that we have currently available to us.”
Jeffrey Barrett, director of the Covid-19 Genomics Initiative at the Wellcome Sanger Institute, said the huge number of cases around the world has given the virus a lot of opportunities to evolve in ways not seen earlier in the pandemic.
“We’re going to have to really contend with these new variants in the virus in the next phase of the pandemic,” he told an online seminar last week. “Something happened that basically allowed a new constellation of mutations to arise,” presenting scientists with new challenges.
The variants likely delay the day when life can get back closer to normal thanks to vaccines and raise the prospect of outbreaks of infections periodically even after large numbers of people are inoculated. And their emergence also suggests that international travel restrictions—where governments impose bans on people coming from places where more troubling versions of the virus are prevalent—could be in place intermittently for years.
The likelihood that many people in poorer countries won’t have access to vaccines for some time suggests that more new variants will be incubating around the world even if levels of immunity in the developed world are high enough to curb the virus’s spread.
The U.K. announcement on Friday that the British variant that now dominates infections across the country—and is also well-entrenched in the U.S.—could be more deadly than earlier versions of the virus is preliminary and could be unduly pessimistic.
It is based on the assessment of an expert advisory panel to the government that in turn used four separate academic studies of raw data to decide that there was a “realistic possibility” that the variant was deadlier.
The studies suggested that a greater proportion of people with this variant were ending up in the hospital or dying. It didn’t suggest that once in the hospital a patient was more likely to die than if he or she had been hospitalized with an earlier variant.
Faster-spreading variants imply that, for any given level of restrictions, cases will rise more rapidly or fall more slowly than with earlier versions. That suggests lockdowns, other things being equal, would have to last longer to bring cases down.
So far, scientists haven’t seen evidence the British variant, first identified in someone in the southeast of England in September, is more resistant to vaccines. But another variant first identified in South Africa has a mutation that could lower the effectiveness of vaccines.
As vaccination programs roll out across the world, they should start to reduce the numbers of people who are seriously ill. If vaccines also confer some immunity as well as prevent serious illness—something so far unknown—they will turn the case curve downward.
Vaccine-resistant variants would slow such downward momentum until scientists tweak vaccines to capture the new variants, too. Some new vaccine technologies, such as those used in the two mRNA vaccines now authorized in the U.S., could be adjusted relatively quickly to deal with new mutations.
Coronaviruses mutate less frequently than certain others, such as influenza viruses that demand an annual vaccination to cope with new variants. However, the virus responsible for Covid-19 appears to be mutating frequently enough to suggest that vaccinated people may need further shots periodically to keep up their protection from the virus.
The good news in the U.K. is that its vaccination program is moving ahead rapidly, faster than any of its European peers. Up to Saturday, nearly 6.4 million people have received at least one coronavirus vaccine dose, and Mr. Hancock said three-quarters of people over the age of 80, as well as people in three-quarters of nursing homes across the country, had received a shot.