No Significant Change in Pathogenicity, but New Strains Evolving

The Chinese Center for Disease Control and Prevention (China CDC) has reported that the dominant COVID-19 variants circulating in China have not shown significant changes in their pathogenicity. However, new strains are emerging that are becoming increasingly immune-evasive.

Globally, three subvariants of the JN.1 strain – KP.3.1.1, KP.3, and LB.1 – are the most prevalent. In China, the major strains in circulation belong to the XDV and JN.1 families, with the proportion of JN.1 infections on the rise.

The China CDC has not observed any significant changes in the pathogenicity of offshoots of XDV and JN.1. The majority of domestic infections with these strains are asymptomatic or only exhibit mild symptoms.

However, the China CDC has also noted that emerging strains are evolving to become more capable of evading existing immunity. The KP.3 strain is likely to become the dominant strain in the future.

"The prevalence of KP.3 in China is low, but its proportion is rising gradually," the China CDC said. "The strain will likely circulate simultaneously with or compete with other major strains such as KP.2 and LB.1 in the future.