China’s Covid wave spurs new variant worry, sequencing falls

Bloomberg

The tsunami of Covid-19 that’s taking hold across China is spurring concern that a dangerous new variant could emerge for the first time in more than a year, just as genetic sequencing to catch such a threat is dwindling.
The situation in China is unique because of the path it’s followed throughout the pandemic. While almost every other part of the world has battled infections and embraced vaccinations with potent mRNA shots to varying degrees, China largely sidestepped both. The result is a population with low levels of immunity facing a wave of disease caused by the most contagious strain of the virus yet to circulate.
The expected surge of infections and deaths are taking hold in China within a black box since the government is no longer releasing detailed Covid data. The rise has medical experts and political leaders in the US and elsewhere worried about another round of disease caused by the mutating virus. Meanwhile, the number of cases sequenced globally each month to find those changes has plunged.
“There will certainly be more omicron subvariants developing in China in the coming days, weeks and months, but what the world must anticipate in order to recognise it early and take rapid action is a completely new variant of concern,” said Daniel Lucey, a fellow at the Infectious Diseases Society of America and professor at Dartmouth University’s Geisel School of Medicine.
“It could be more contagious, more deadly, or evade drugs, vaccines and detection from existing diagnostics.”
The closest precedent to what could happen, Lucey says, is the experience with the delta variant in India in late 2020 when millions of people were infected over a short period of time and the deadly strain raced around the globe. While it’s not inevitable, the world must protectively prepare for such an event so that vaccines, treatments and other necessary measures can be ready, he said.
China is closely watching omicron subvariants circulating in the country, Xu Wenbo, director at the National Institute for Viral Disease Control and Prevention, said at a briefing in Beijing. It has established a national Covid viral sequencing database, which will receive genetic sequences from three hospitals in every province each week to catch any emerging variants, he said.
“This will allow us to monitor in real-time how omicron subvariants are circulating in China and their makeup,” he said.
There is little clarity now about infections and deaths in China, after the country largely abandoned its mass testing regime and narrowed the way it measures Covid mortality.
There are two paths the virus could take in China. Omicron and its hundreds of subvariants may sweep directly through, likely in several waves, leaving no room for other contenders – as it has in the rest of the world for all of 2022. Vaccination and infections will boost immunity until eventually antibodies in the population will help control serious disease.