Arcturus COVID variant: What you need to know

The emergence of a new strain of COVID in India has led to an increase in infections and raised concerns. Recent research suggests that this strain, known as Arcturus or Omicron subvariant XBB.1.16, may be 1.2 times more infectious than the previous major sub-variant. 

The World Health Organisation (WHO) has been monitoring this strain since 22 March and has identified one additional mutation in the spike protein that could increase its infectivity and potential pathogenicity, although no changes in severity have been observed so far. 

What do we know about Arcturus COVID variant?

This sub-variant has been detected in 22 countries, including the UK and the US, and is not currently considered more lethal than other strains. In India, where the Delta wave caused widespread devastation in 2021, the government has introduced measures such as compulsory face masks and hospital drills to contain the spread of this new strain, while also ramping up vaccine production. 

According to WHO estimates, India suffered a total of 4.7 million excess deaths due to COVID during the Delta wave.

According to Dr Vipin Vashishtha, a paediatrician and former head of the Indian Academy of Pediatrics Committee on Immunisation, the symptoms of Arcturus include a high fever, cough, and "itchy" conjunctivitis or pinkeye, as reported by The Hindustan Times. 

While The Daily Mail reported around 50 cases detected in the UK, Professor Paul Hunter from the University of East Anglia cautioned that it is premature to conclude that the country may experience another wave of infections caused by Arcturus.

“Although in India it has taken off in the past few weeks so far it has not been increasing rapidly globally,” Professor Hunter was quoted in The Independent.

“I suspect we will see a wave of infections with this variant but I doubt it will cause a big wave probably not even as great as the one we have just had in the UK and so probably not put as great a pressure on health services than recently.”

The professor referred to the Kraken strain, also known as XBB.1.5, which was the predominant form of COVID in the UK until February. Scientists at the University of Tokyo have compared the Kraken and Arcturus sub-variants and found that the newer strain spreads approximately 1.17 to 1.27 times more effective than its relative. 

They have also cautioned that the strain is "robustly resistant" to antibodies in the body from previous COVID infections, and they predict that it will spread globally soon. Virologist Professor Lawrence Young from the University of Warwick told The Independent that the emergence of the new variant in India indicates that "we're not yet out of the woods."

“We have to keep an eye on it,” he said.