What to know about ‘Arcturus’, the new COVID variant spreading in India, US

A new variant of COVID-19, XBB.1.16, has captured the world’s attention in recent weeks, driving curiosity and eliciting questions.

The variant, nicknamed ‘Arcturus’ on social media, has become increasingly common in some countries, and according to the US Centre for Disease Control (CDC), it now makes up more than 11 percent of all cases in the country.

What is the variant and when was it reported?

According to the World Health Organisation, XBB.1.16 is a descendant of the Omicron variant and has a similar genetic profile as the XBB.1.5 sub-variant. It is one of 600 Omicron sub-variants circulating the world. 

Though its origins were not stated, the WHO said the subvariant was first reported on January 9, 2023. The organisation designated XBB.1.16 a variant under monitoring (VUM) on March 22, 2023, which meant the variant had genetic changes ‘suspected’ to alter its characteristics and give it an advantage over other existing variants.

On April 17, however, it was designated a variant of interest (VOI); one with genetic changes ‘known’ to affect its characteristics and identified to have an advantage over other existing variants.

Which countries have the variant been found in?

The XBB.1.16 variant has been reported in over 30 countries with the majority of the sequences found in India.

Other countries that have reported at least 50 sequences of the variant include the US, Singapore, Australia, Canada, Brunei, Japan and the UK.

How dangerous is this new variant?

The WHO says the global risk assessment for XBB.1.16 is low compared to XBB.1.5 and the other currently circulating variants.

While the subvariant has been observed to have growth advantage and immune escape properties, no changes in severity have been reported in countries it is said to be circulating. The global health body, however, warned that the subvariant may become dominant in some countries in coming weeks.

Does the variant have new symptoms?

Mike Ryan, executive director of the WHO’s health emergencies programme, said during a media briefing that XBB.1.16 doesn’t appear to be making people sicker than earlier omicron strains.

“To my knowledge, we’re not seeing a different spectrum of symptoms or severity associated with this variant of interest,” he said.

However, some news reports have said the subvariant causes conjunctivitis, or ‘pink eye’.

According to the American Academy of Ophthalmology, conjunctivitis is suspected to be a symptom of the subvariant, particularly among children.

The AAO said if children have itchy, red eyes, parents shouldn’t be alarmed but should, however, carry out COVID testing to rule out the virus. 

Will available vaccines work against the variant?

It is not yet known just how protective the current vaccines are against XBB.1.16.

But the Los Angeles County department of public health said in a recent statement that because XBB.1.16 is a descendant of the Omicron variant, “current vaccines and therapeutics are highly likely to remain protective and able to ward off severe illness”.