An analysis of COVID-19 cases in Beijing since the gradual lifting of strict virus control policies began in November suggests that no new variants emerged from China's recent outbreak, according to a study released on Thursday.

Researchers led by Gao Fu, from the Institute of Microbiology at the Chinese Academy of Sciences, conducted genome analysis of 413 COVID-19 cases in the capital between Nov 14 to Dec 20.

The study was published in The Lancet, an international peer-reviewed journal, on Thursday.

Results showed that all the cases — 350 domestic infections and 63 imported — belonged to known strains, and more than 90 percent of local infections involved two Omicron subvariants, BA.5.2 and BF.7.

"Although our data were only from Beijing, the results could be considered a snapshot of China, due to the frequent population exchanges and the presence of circulating strains with high transmissibility," the study said.

It concluded that no novel COVID-19 variants had emerged during China's recent outbreak.

"Our analysis suggests two known Omicron subvariants — rather than any new variants — have chiefly been responsible for the current surge in Beijing, and likely China as a whole," Gao said.

He added that with the ongoing spread of the disease in the country, it is important to continue to monitor the situation closely so that any potential emerging variant can be detected promptly.