HONG KONG – Analysis of COVID-19 cases in Beijing suggests no new variants have emerged from the recent outbreak in China, according to a study released Wednesday.
Facing rare mass unrest after nearly three years of strict “zero-Covid” policies, the Chinese government lifted most restrictions on Dec. 7. The sudden change unleashed the coronavirus over winter on a population of 1.4 billion people who had barely been exposed to it, raising fears that the epidemic could produce a new variant of concern and leading dozens of countries, including the United States, to impose tests and other limits on travelers from China.
But the Chinese-funded study, published in The Lancet, found that out of 413 infections sampled in Beijing, all belonged to existing Covid variants. The most common were the omicron subvariants BA.5.2 and BF.7, which together accounted for more than 90% of local infections.
Samples were randomly selected for genomic sequencing from a larger pool of 2,881 high-quality samples collected in Beijing from November 14 to December 20, 2022.
George Gao, the study’s lead author and a professor at the Institute of Microbiology of the Chinese Academy of Sciences, said it was important to investigate whether new variants emerged during the Chinese outbreak, given the impact that others such as deltas and omicrons have had on the course of the pandemic.
“Our analysis suggests that two known subvariants of omicron – rather than any new variants – were primarily responsible for the current surge in Beijing, and likely China as a whole,” said Gao, the former director of the China Center for disease control and prevention. in a press release.
“However, with the continued large-scale circulation of COVID-19 in China, it is important to continue to monitor the situation closely in order to identify any new variants that may emerge as soon as possible.”
Although the study covered a short time at the start of the outbreak and sampling was limited to Beijing, its findings are in line with reports from Italy and other countries that have tested arrivals from China for Covid and sequenced the results. said Tongai Maponga, a researcher at the Division of Medical Virology at Stellenbosch University in South Africa.
“Whatever they’re detecting in travelers from China is the same thing we already know is circulating elsewhere,” said Maponga, who was not involved in the Beijing study.
The study was also limited by the fact that China ended large-scale mandatory testing in December, making it difficult to know the total number of cases in the outbreak and therefore what percentage of the total cases the samples represent.
After being held at bay for most of the pandemic, the virus appears to have swept through China much faster than many other countries, starting to pick up speed last fall even before Covid restrictions were lifted. Beijing and other major cities have experienced some of the first outbreaks.
Zeng Guang, a former chief epidemiologist at China’s CDC, said in late December that more than 80 percent of Beijing residents had most likely contracted the virus. A study released in January by researchers at the University of Hong Kong said it could be over 92% by January 31.
Chinese officials say a feared surge during the Lunar New Year holiday period, when hundreds of millions of people travel to their hometowns to visit family and which began in mid-January, has failed to materialise. But the outbreak was still a huge source of anxiety for Chinese who had been taught to fear Covid-19 and devastating for those who have lost loved ones to the disease.
Global fears that a new variant could emerge have been compounded by what the World Health Organization and others have said is a lack of data from China on its outbreak. China has defended its data and criticized the travel measures as unscientific and discriminatory.
Chinese officials have released more data in recent weeks, saying hospitals have recorded around 80,000 Covid-related deaths since early December. Many experts say the true number is much higher, with British meteorologist Airfinity estimating 608,000 deaths from December 1 to January 17.
China’s CDC recently reported 3,278 Covid-related deaths nationwide from Jan. 27 to Feb. 2, about half the number from the previous week. It says daily Covid infections peaked at 6.94 million on December 22 and have since dropped to around 24,000 as of January 30.
Maponga stressed that a new variant of concern could yet emerge anywhere in the world, emphasizing the need for continued testing, genomic surveillance and transparent data sharing.
“As long as it keeps circulating, infecting people and animals, the virus will always develop mutations because that’s the nature of viruses,” he said.
This article was originally published on NBCNews.com