Omicron subvariant spreading slowly in China

The new Omicron subvariant XBB.1.16 is spreading at a very low rate in China, the National Administration of Disease Control and Prevention said on Friday.

Although the proportion of XBB.1.16 cases in imported infections is growing, the variant has not dominated domestic circulation, the administration said.

The new variant, also known as Arcturus, was first detected in January and began spreading in various countries, including India, the United States, Singapore and Australia.

As of Tuesday, at least 33 countries and regions had reported over 3,600 infections with XBB.1.16. It has already become the dominant strain in India and is rising rapidly in the United States.

On March 22, the World Health Organization designated XBB.1.16 as a new variant under monitoring.

"Due to its estimated growth advantage and immune escape characteristics, XBB.1.16 may spread globally and contribute to an increase in case incidence. However, at present, there is no early signal of an increase in severity," said the WHO in its latest COVID-19 weekly update released on Thursday.

According to the administration, the variant carries an additional mutation in the spike protein, making it more transmissible and is as equally immune evasive as its ancestor strain, XBB.1.

The new strain does not appear to trigger more serious symptoms, but it could cause severe cases in children, the elderly and those with weakened immune systems.

There are reports that the new strain may cause red, itchy eyes, especially among children.

"Such symptoms have also been observed in previous strains. Patients experiencing such conditions should seek treatment from doctors as soon as possible," it said.

The administration added that immunity gained from vaccinations or a recent infection can protect against the new strain. Mask use is recommended for vulnerable groups as well as in facilities with large gatherings.

According to the Chinese Center for Disease Control and Prevention, BA.5.2, BF.7 and their descendants now account for the majority of domestic cases.

Zhang Wenhong, head of the infectious disease department at Fudan University's Huashan Hospital in Shanghai, said during a forum on Thursday that the proportion of XBB infections is expected to gradually rise domestically as it accelerates its spread worldwide.

He said it remains unknown whether a highly pathogenic strain would emerge in the future, but China has active monitoring systems in place to promptly detect importation of new strains and evaluate their threats to health.