© May James / Zuma Press
The emergence of new variants of the virus that causes Covid-19 – including one in the UK that British officials say could be more deadly than previous versions – signals a future in which health officials are trapped in a battle of cat and mouse with a pathogen that changes shape.
The faster-spreading coronavirus strains that researchers fear can also make people sicker or make vaccines less effective, threaten to extend blockages and lead to more hospitalizations and deaths, epidemiologists warn. But, they said, that does not mean that contagion cannot be contained.
“We are living in a world where the coronavirus is so prevalent and mutates rapidly that new variants will emerge,” said Anthony Harnden, a doctor who advises the UK government, to Sky News. “We may very well be in a situation where we will end up having to have an annual coronavirus vaccine” to deal with emerging strains.
As the new variant in the UK has spread across the country, hospitals are under more pressure than in the first wave of the pandemic in the spring, and the national death toll from Covid-19 is expected to exceed 100,000 in the coming days. But in the week ending on Sunday, new daily cases dropped 22% from the previous seven days.
UK health secretary Matt Hancock said this was due to national restrictions in place since the beginning of the year. But in a television interview, Hancock warned, “We have a long, long, long way” before cases were low enough that restrictions were lifted.
The UK variant is one of several that have emerged in recent months to cause concern among researchers. Others appeared in South Africa and Brazil.
Anthony Fauci, President Biden’s chief medical advisor for the Covid-19 pandemic, said on CBS on Sunday that U.S. officials need to expand genomic surveillance to identify variants of the virus.
Dr. Fauci said that current vaccines remain effective. “What we are going to do and are already doing is preparing ourselves for the possibility that, in the future, we may need to modify and update the vaccines. We don’t have to do that 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 currently have available to us.”
Jeffrey Barrett, director of the Covid-19 Genomics Initiative at the Wellcome Sanger Institute, said the sheer number of cases worldwide has given the virus many opportunities to evolve in ways not seen before in the pandemic.
“We will really have to face these new variants of the virus in the next phase of the pandemic,” he said at an online seminar last week. “Something happened that basically allowed a new constellation of mutations to emerge”, presenting scientists with new challenges.
The variants are likely to delay the day when life can return to normal thanks to vaccines and increase the prospect of outbreaks of infection periodically, even after a large number of people are inoculated. And its emergence also suggests that restrictions on international travel – where governments impose bans on people who come from places where the most worrying versions of the virus are prevalent – could be applied intermittently for years.
The likelihood that many people in poorer countries will not have access to vaccines for some time suggests that more new variants will be incubating around the world, even if immunity levels in the developed world are high enough to stem the spread of the virus.
The UK’s announcement on Friday that the British variant that now dominates infections across the country – and is also well rooted in the United States – may be more deadly than previous versions of the virus is preliminary and may be unduly pessimistic.
It is based on the assessment of an expert advisory panel for the government, which in turn used four separate academic studies of raw data to decide that there was a “realistic possibility” that the variant was more deadly.
Studies suggested that a greater proportion of people with this variant ended up in the hospital or died. This does not suggest that, once in the hospital, the patient is more likely to die than if he or she had been hospitalized with a previous variant.
Variants of faster spread imply that, for any level of restriction, cases will increase more quickly or decrease more slowly than in previous versions. This suggests that the blocks, if the other factors remain the same, would have to last longer to close the cases.
So far, scientists have seen no evidence that the British variant, first identified in someone in southeastern England in September, is more resistant to vaccines. But another variant first identified in South Africa has a mutation that could decrease vaccine effectiveness.
As vaccination programs are implemented around the world, they must begin to reduce the number of seriously ill people. If vaccines also confer some immunity, as well as preventing serious illnesses – something hitherto unknown – they will turn the case’s curve downwards.
Vaccine-resistant variants would delay this downward momentum until scientists adjusted the vaccines to capture the new variants as well. Some new vaccine technologies, such as those used in the two mRNA vaccines now authorized in the United States, could be adjusted relatively quickly to deal with new mutations.
Coronaviruses mutate less frequently than some others, such as influenza viruses, which require an annual vaccination to deal with new variants. However, the virus responsible for Covid-19 appears to be mutating frequently enough to suggest that vaccinated people may need more injections periodically to maintain their protection against the virus.
The good news in the UK is that its vaccination program is advancing rapidly, faster than any of its European peers. As of Saturday, nearly 6.4 million people have received at least one dose of the coronavirus vaccine, and Hancock said that three quarters of people over 80, as well as people in three quarters of nursing homes across the country, received a shot.
Write to Stephen Fidler at [email protected]
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