The worry is that the sudden spread of Covid through a new population with relatively little previous exposure to the virus will lead to the emergence of a new “super-variant”—one with the ability to change the situation of pandemics like Alpha, Delta. , and other forms of the virus Omicron have done before. But whether there is a significant risk of this happening remains unclear.
In 2020, Ravi Gupta, professor of clinical microbiology at the University of Cambridge, published a paper in magazine Nature demonstrated that chronic infection with SARS-CoV-2—where the virus survives and multiplies inside the bodies of people with compromised immune systems—offers a greater opportunity for the virus to evolve. “A billion new infections means more opportunities for chronic infections,” Gupta said. “You’re raising the numbers game in favor of the virus to create new, potentially problematic variants.”
But Cowling argues that because immunity levels are much lower in China than in the rest of the world, the virus should be relatively easy to spread among the population without having to evolve. He said that if a new super variant emerges, it is more likely to come from North America or Europe, where many people have developed immunity through both vaccinations and previous infections.
“My intuitive instinct is that the risk of a new major variant might not be higher in China,” says Gupta. “For example, in the UK, if Covid continues to circulate, it has to find a new direction and a way to avoid immunity to previous waves of Omicron and all its sub-variants, while In China, it’s still spreading quite happily.”
Even if a new supervariant emerges, scientists aren’t sure if it will be more or less toxic than what’s already there. Last year, Gupta et al show that Omicron is less lethal than its predecessors because it does not effectively infect lung cells. “Instead, it infects the nasal cells,” he said. “Omicron chose a route that exists in the upper respiratory tract, so it’s less severe and transmits very well.”
But Gupta cautions that this doesn’t necessarily mean the virus’s entire trajectory has turned less severe, and says it still makes biological sense for a more virulent version to emerge. . “There is no evolutionary reason why the virus could not return to full pathogenicity,” he said.
Whatever happens, it may be some time before the full consequences of the Covid-19 outbreak in China become apparent. While some global corporations such as GISAID in Germany still specializes in tracking coronavirus mutations, in general, countries around the world have downsized their efforts to sequence virus samples, making it difficult to track new variants and how they are introduced. introduction to different countries becomes more difficult. “People have realized how much it costs, and it’s not just in the UK and US—it’s happening globally,” says Gupta. “So for that reason, we may be most vulnerable at the moment, in a relative sense, just because we don’t know what’s out there.”
For much of Europe and North America, Balloux describes Covid as now comparable to many other common respiratory infections, though that picture could change if a dangerous new super variant emerges. . The alarming spikes in cases, hospitalizations and deaths in 2020 and 2021 have been replaced by a more steady, insidious death toll.
From January to November 2022, 41,620 people in the UK died of Covid. Most are thought to be elderly people who are already frail and have multiple underlying health conditions, or people with suppressed immune systems — either due to illness or because they are taking medication — although no data are available. whether accurate. By comparison, a particularly severe flu season tends to result in about 30,000 deaths.
“There are very few healthy young people dying of Covid in the UK or the US right now,” Balloux said. “What Covid is doing at the moment is essentially adding stress to other problems — people who already have underlying problems and the fact that in the UK the hospital system just can’t cope. It is amplifying these underlying risks.” China’s rise in Covid, at least for now, won’t change many of the already-existing threats the virus poses.