The emergence of new variants of the virus that causes Covid-19 – including in the UK, which the British authorities say could be more deadly than earlier versions – signals a future in which health authorities are locked in battle of cat and mouse with a pathogen that changes shape.
Faster-spreading coronavirus strains, which researchers fear could also make people sick or make vaccines less effective, threaten to prolong blockages and lead to more hospitalizations and deaths, epidemiologists warn. But, they said, that doesn̵
“We live in a world where the coronavirus is so prevalent and rapidly mutating that new variants will emerge,” Anthony Harndon, a doctor who advises the British government, told Sky News. “We may be in a situation where we eventually have to have an annual coronavirus vaccine” to deal with emerging strains.
As the new variant has spread across the country across the country, hospitals are under more strain than in the first wave of the pandemic in the spring, and national Covid-19 casualties are expected to exceed 100,000 in the coming days. But in the week ending Sunday, new daily cases fell 22 percent from the previous seven days.
Matt Hancock, the UK’s health minister, said this was due to national restrictions imposed since the beginning of the year. But in a television interview, Mr Hancock warned: “We are a long, long, long way” before the cases are low enough to lift the restrictions.
The option for the United Kingdom is one of several that have emerged in recent months to cause concern among researchers. Others have appeared in South Africa and Brazil.
Anthony Fauci, President Biden’s chief medical adviser on the Covid-19 pandemic, told CBS on Sunday that US authorities should expand genomic surveillance to identify variants of the virus.
Dr Fauci said current vaccines remain effective. “What we are going to do and are doing now is to prepare for the possibility that down the pipe, down the line, we may need to modify and upgrade the vaccines. We don’t have to do that right now, “he said. “The best way to prevent these mutants from developing further is to vaccinate as many people as possible with the vaccines we currently have.”
Jeffrey Barrett, director of the Covid-19 Genomics Initiative at the Wellcome Sanger Institute, said the sheer number of cases around the world has given the virus many opportunities to grow in ways not previously seen in the pandemic.
“We will really have to fight 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,” introducing scientists to new challenges.
The options probably slow down the day when life can return to normal thanks to vaccines and raise the prospect of outbreaks periodically, even after a large number of people have been inoculated. And their emergence also suggests that restrictions on international travel – where governments impose bans on people coming from places where more disturbing versions of the virus predominate – may exist periodically 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 incubated around the world, even if immunity levels in developed countries are high enough to limit the spread of the virus.
Britain’s announcement on Friday that the British version, which now dominates infections across the country – and is also well established in the United States – could be more deadly than earlier versions of the virus was preliminary and could be overly pessimistic.
It is based on the assessment of an expert advisory panel to the government, which in turn uses four separate academic studies of raw data to decide that there is a “realistic possibility” that the option would be more deadly.
Studies show that most people with this option are hospitalized or die. It does not suggest that once in the hospital, the patient is more likely to die than if he or she was hospitalized with an earlier variant.
Faster-spread variants suggest that for a given level of constraints, cases will rise faster or fall more slowly than in earlier versions. This suggests that the blockades, other things being equal, will have to last longer to reduce cases.
So far, scientists have seen no evidence that the British variant, first identified in someone in the south-east of England in September, is more resistant to vaccines. But another option, first identified in South Africa, has a mutation that could reduce the effectiveness of vaccines.
As vaccination programs spread around the world, they must begin to reduce the number of people who are seriously ill. If vaccines also give some immunity, as well as prevent serious diseases – something unknown so far – they will turn the case down.
Vaccine-resistant variants would slow such a decline until scientists change vaccines to capture new variants. Some new vaccine technologies, such as those used in the two mRNA vaccines that are now approved in the United States, can be adjusted relatively quickly to deal with new mutations.
Coronaviruses mutate less frequently than some others, such as influenza viruses, which require annual vaccination to deal with new variants. However, the virus responsible for Covid-19 appears to mutate often enough to suggest that vaccinated people may periodically need additional photos to maintain protection against the virus.
The good news in the UK is that the vaccination program is evolving fast, faster than any of its European peers. By Saturday, nearly 6.4 million people had received at least one dose of coronavirus vaccine, and Mr Hancock said three-quarters of people over the age of 80, as well as three-quarters of nursing homes nationwide, had received shot.
Write to Stephen Fiedler at email@example.com