China has detected over 130 sublineages of Omicron in the past three months, including the highly watched BQ.1 and XBB strains, but their pathogenicity remains unchanged, an expert said on Tuesday.

Xu Wenbo, head of the National Institute for Viral Disease Control and Prevention with the Chinese Center for Disease Control and Prevention, said that nine provincial-level regions have reported 49 cases of the BQ.1 strain, and three provincial-level regions have registered 11 XBB cases, but the dominant strains on the mainland remain BA.5.2 and BF.7.

"The BQ.1 and XBB strains have higher transmissibility and are more capable of evading immunity, but their pathogenicity has not risen," he said during a news conference. "As they become dominant in some foreign countries, there is no report pointing to rising rates of severe cases and deaths caused by these two strains."

Xu added that 50 of the 130-plus sublineages have triggered local infection clusters.

"These sublineages, along with the current dominant strains of BA.5.2 and BF.7, will likely co-circulate in the country in the future," he said.

Xu said that the Chinese CDC will continue to monitor pathogenicity and genome sequencing of new variants.