China strengthens surveillance of Covid variants as countries impose entry restrictions
China is ramping up surveillance for variants of Covid-19 as an unprecedented wave of coronavirus hits its population, causing worldwide alarm and introducing new restrictions on travelers. from this country.
In recent days, Chinese researchers and officials have begun uploading genome sequence data from hundreds of Coronavirus sample for Gisaid, a global online database that allows scientists to track virus mutations.
Data, although limited, suggest that major Omicron sub-variants are widespread in China similar to those identified in Europe and North America, where they are mostly competed by more virulent strains.
A research team at a major university in Beijing that has begun sending sequenced samples from the city says about 80% of their specimens are the Omicron BF.7 sub-variant, while 20% are BAs. .5.2. Both are by-products of strain BA.5.
“The sample size is small so we still need more data to get the full picture,” said one member of the research team, who requested anonymity.
These findings are consistent with statements from Chinese health officials, who have said that two Omicron sub-variants are responsible for the majority of cases in the country, as well as other samples uploaded to Gisaid. from Fujian, Guangdong, Sichuan and other provinces.
Data from the US Centers for Disease Control and Prevention estimated that the BA.5 sub-variant was responsible for 80% of Covid-19 cases in the US in September, but had dropped to 7% by mid-Dec. BF.7 was found in 7% of US samples in November and only 4% in the week to December 24.
This month, Xu Wenbo, a top official at the Chinese Center for Disease Control and Prevention, said the agency is developing a national genetic database of Covid samples.
Xu said three hospitals in each province will take samples from at least 25 Covid patients each week, but it is not yet clear whether the system has been put into operation. Health officials are struggling to cope with a large influx of elderly Covid patients who have Hospitals and emergency services are overwhelmed.
Beijing’s move to limit most Covid testing while publishing unbelievably low mortality figures has increased uncertainty that it is once again covering up information to cover up the extent of the outbreak. outbreak, as when Covid was first detected in Wuhan.
China’s top health officials last week estimated the country alone at seeing 37 million new infections every day, with the rate of spread of Covid is still increasing. Airfinity, a UK-based health data group, has forecast 1.7 million deaths across China by the end of April 2023.
The United States on Wednesday cited data “lack of complete data and transparency” when it announced Covid testing requirements for air travelers from China.
Japan, India, Taiwan, South Korea and Italy have also imposed restrictions on Chinese visitors in the face of a wave of visitors. when the country reopens its borders. Italy found that more than half of the passengers on a post-Christmas flight from China to Milan were infected, but on Thursday said no new variants had been found among the resolved cases. sequence.
Gisaid said that in the past week, China has submitted nearly a thousand virus genomes, and that provincial offices with the China CDC have “significantly increased the number of genome sequencing and related metadata submissions from samples”.
The head of a Chinese Covid vaccine maker said health officials were very concerned that sub-variants such as XBB and BQ, which are common elsewhere, would create a second wave of Covid-19 in the country. coming months. Gisaid data shows that strains of the virus have started circulating in Shanghai.
“With the outbreak being so widespread, it’s almost certain that China will eventually have its own variant, we just don’t know how serious or dangerous it is,” he added.
Ben Cowling, a professor of epidemiology at the University of Hong Kong, said it was reasonable to be wary of new variants emerging in China, but added that “more sequencing would be better from all the nations”.
“It’s not fair to say that only China should do more sequencing,” he said.