No new Covid variants appear to have emerged during the recent outbreak in China. This is suggested by the outcome of an analysis conducted on a sample of cases in Beijing and published in ‘The Lancet’. The authors examined the viral sequences of 413 new SARS-CoV-2 infections that occurred around the time the Asian giant lifted its tougher pandemic control policies. These infections were caused, according to the results obtained, by existing strains. Over 90% of local infections in Beijing between November 14 and December 20, 2022 revealed the presence of the Omicron subvariant BA.5.2 or BF.7. The cases imported during the same period mostly concerned variants other than those dominant in Beijing.
The authors say the findings can be considered a snapshot of the current state of the pandemic in China. “Given the impact that variants have had on the course of the pandemic, it was important to investigate whether new variants had emerged,” said lead author of the study George Gao, Institute of Microbiology of the Chinese Academy of Sciences. The country famously concluded its zero-Covid strategy on December 7, 2022. Since the abolition of these stringent policies that included targeted lockdowns, mass testing and quarantines, the rising number of cases has raised international concerns over the that new variants could emerge, causing multiple waves of cases around the world.
Of the more than 400 samples tested, 350 were local cases and 63 were imported. The imported cases came from 63 countries and regions. The dominant strain in Beijing after November 14, 2022 was BF.7, which accounted for 75.7% of local infections. Another subvariant of Omicron, BA.5.2, was responsible for 16.3% of local cases. “It is important to continue to monitor the situation closely so that any new variants that may emerge are identified as soon as possible,” concludes Gao.