Masked commuters cross a walkway between two subway stations as they go to work during the morning rush hour in Beijing, Dec. 21, 2019. 20. (Andy Wong, Associated Press)
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BALTIMORE — Could China’s COVID-19 surge unleash a novel coronavirus mutant into the world?
Scientists don’t know, but fear it might happen. It might look like omicron variants now circulating there. It could be a combination of strains. Or something completely different, they say.
“China has a very large population and immunity is limited. And that seems to be the setting where we could see an explosion of a new variant,” said Dr. Stuart Campbell Ray, an infectious disease expert at the ‘Johns Hopkins University.
Each new infection gives the coronavirus a chance to mutate, and the virus is spreading rapidly in China. The country of 1.4 billion people has largely abandoned its “zero COVID” policy. Although reported overall vaccination rates are high, recall rates are lower, particularly among the elderly. Domestic vaccines have been shown to be less effective against serious infections than Western-made messenger RNA versions. Many were given more than a year ago, which means immunity wanted.
The result? Fertile ground for the virus to change.
“When we’ve seen large waves of infection, they’re often followed by the generation of new variants,” Ray said.
about three years ago, The original version of the coronavirus spread from China to the rest of the world and was eventually replaced by the delta variant, then omicron and its descendants, which continue to plague the world today.
Dr. Shan-Lu Liu, who studies viruses at Ohio State University, said many existing omicron variants have been detected in China, including BF.7, which is extremely adept at evading immunity. and who would be behind the current surge.
The experts said a partially immune population like that of China puts particular pressure on the virus to change. Ray compared the virus to a boxer who “learns to escape the skills you have and adapt to work around them”.
A big unknown is whether a new variant will cause more severe disease. Experts say there is no inherent biological reason for the virus to wane over time.
“Much of the mold we have seen over the past six to 12 months in many parts of the world is due to built up immunity either through vaccination or infection, not because the virus has changed” in severity, Ray said.
In China, most people have never been exposed to the coronavirus. Chinese vaccines rely on older technology that produces fewer antibodies than messenger RNA vaccines.
Faced with these realities, Dr. Gagandeep Kang, who studies viruses at Christian Medical College in Vellore, India, said it remains to be seen whether the virus will follow the same pattern of evolution in China as in the rest of the world. world after the release of vaccines. Or, she asked, will the pattern of evolution be completely different?
Recently, the World Health Organization expressed concern over reports of serious illness in China. Around the cities of Baoding and Langfang outside Beijing, hospitals are running out of intensive care beds and staff as severe cases rise.
China’s plan to track the virus centers around three municipal hospitals in each province, where samples will be taken from walk-in patients who are very sick and all those who die each week, said the Center’s Xu Wenbo. Chinese Disease Control and Prevention at a briefing on Tuesday.
He said 50 of the 130 versions of omicron detected in China led to outbreaks. The country is creating a national genetic database “to monitor in real time” the evolution of different strains and potential implications for public health, he said.
At this point, however, information on genetic viral sequencing from China is limited, said Jeremy Luban, a virologist at the University of Massachusetts Medical School.
“We don’t know everything that’s going on,” Luban said. But clearly, “the pandemic is not over”.
contributor: Dake Kang
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