Q&A on emerging XBB.1.16 variant

chinacdc.cn | Updated: 2023-04-25

What is XBB.1.16?

XBB.1.16, also known as "Arcturus", is a recombinant strain of the omicron variant, which is one of over 600 variants circulating globally and one of 137 XBB subfamilies. It was first detected in January and has been spreading in countries and regions such as India, the United States, Singapore and Australia.

It was officially named on March 5. The newly added mutation sites on the S protein of XBB.1.16 make it easier to spread than the parent XBB.1 and its immune escape ability is equivalent to that of XBB.1.5.

How widespread is XBB.1.16 globally?

As of April 18, at least 33 countries and regions worldwide have reported 3,647 sequences of the XBB.1.16 variant, mainly from India (63.4 percent), the United States (10.9 percent), and Singapore (6.9 percent).

Since March, the proportion of the XBB.1.16 sequences reported in India has grown rapidly and become the main epidemic strain. XBB.1.5 is still the dominant variant in the United States, but the proportion of XBB.1.16 and XBB.1.9.1 cases has increased recently.

Due to the prevalence of XBB.1.16 in Asian countries, the proportion of imported XBB.1.16 cases in China has also increased.

What are the characteristics of XBB.1.16?

Studies have shown that the transmission rate of XBB.1.16 is slightly higher than that of XBB.1 and XBB.1.5 variants and the immune escape ability of XBB.1.16 is equivalent to that of XBB.1.5.

At present, there are no reports of hospitalization or increased deaths due to infection with XBB.1.16, nor have there been reports of higher disease severity compared to other Omicron sub-variants. However, for vulnerable groups such as children, the elderly and those with underlying diseases, severe symptoms may occur due to individual differences.

Can XBB.1.16 cause conjunctivitis?

It has been reported that XBB.1.16 can cause itching and redness (conjunctivitis) in children's eyes. Similar ocular symptoms have also been reported in the previous variant waves. If such symptoms appear, people should seek medical assistance and treatment.

How can we protect ourselves?

At present, the immunity provided by vaccination or previous infections can still provide individuals with a certain degree of protection. Individuals are advised to continue practicing personal protective measures and wear masks in public places.