Arcturus: What you need to know about the 'one to watch' COVID variant and its new symptoms

The World Health Organization (WHO) is carefully monitoring a new Omicron subvariant that is driving a surge of new COVID-19 cases in India.

XBB.1.16 - also known as "Arcturus," the name of the brightest star in the northern celestial hemisphere - was detected in 21 countries as of March 27.

The WHO upgraded it to "variant of interest" status in mid-April, with the number of countries now affected believed to be 34.

Scientists at the University of Tokyo suggest it could be about 1.17 to 1.27 times more infectious than Kraken, the last major omicron sub-variant, making it likely to become the next dominant strain. "This is one to watch," said Dr Maria Van Kerkhove, technical lead for COVID-19 response at the WHO, during a press conference on March 29.

Since the beginning of the coronavirus pandemic, the global health body has designated three labels to assess the potential risk of new COVID-19 strains: “variants of concern,” “variants of interest,” and “variants under monitoring”.

Variants are assigned into either category based on several respects, such as their predicted potential for expansion and probability of causing new waves, for example.

According to the WHO’s variant tracking, Alpha, Beta, Gamma, Delta and the Omicron parent lineage are now all considered "previously circulating VOCs [variants of concern]".

Arcturus, on the other hand, is now considered a VOI because of the "spread of the virus beyond borders," tweeted Muhammad Munir, Professor of Virology & Viral Zoonoses at Lancaster University in the UK.

"Because XBB.1.16 is more transmissible and possibly escaping immunity, it may become dominant in the coming months," he added.

Arcturus, which was first identified in January, does not appear to be more severe than