Cases of COVID-19 infection by an evolved sublineage of Omicron's BA.2 mutation, Omicron BA.2.3, were reported on Monday in Yantai, East China's Shandong Province, the first time the strain has been detected in the China.
Genetic sequencing shows that 16 cases reported in the port city belong to the same transmission chain, caused by this evolved variant, the city's health authorities said at a news conference on Monday. The new variant has proven to be more contagious with a shorter incubation period.
Yantai reported 36 confirmed COVID-19 cases, along with 34 silent carriers on Sunday. The city has recorded an increasing number of cases in recent days. It has vowed to quickly stamp out all transmissions, and to eliminate viral infections within communities as soon as possible.
Meanwhile, immunologists said that the emergence of this new strain in China is not expected to make a major difference to the country's epidemic fight. There is a high possibility that this strain was imported from outside of the mainland.
Current data has shown no evidence of significant changes in BA.2.3's infectiousness and immune escape capacity, but a growing number of cases have been reported in some countries.
The strain's relative growth advantage is 17 percent globally, implying that it is causing more infections worldwide.
According to the results of the global sequencing of the COVID-19 gene, Omicron BA.2.3 has now been detected in 49,000 sequences worldwide, accounting for 6.2 percent of all strains, Zhuang cited data as saying. Most of the previous cases were found in Europe.
