A new subvariant of the coronavirus has been gaining steam in recent weeks as it has spread to several countries including the United States.
The XBB.1.16 subvariant, a member of the omicron variant’s lineage that has been nicknamed Arcturus, has become increasingly common in the U.S. recently, making up almost 10 percent of all cases last week. Only the XBB.1.5 subvariant, which made up almost three-quarters of cases last week, is more common.
The subvariant was first reported in January, and the World Health Organization (WHO) in March declared it a variant under monitoring – a variant with genetic changes that are suspected to alter its characteristics and give it an advantage over other existing variants.
It has been seen in other countries like Singapore, Australia and Canada.
WHO designated it to be a variant of interest, a variant with genetic changes that are predicted or known to affect its characteristics and identified to have an advantage over other existing variants, on April 17. The characteristics could include transmissibility and virulence.
Despite the increasing categorization for the subvariant, WHO does not believe that Arcturus has an additional public health risk compared to XBB.1.5 and other omicron descendants. The organization said in its initial risk assessment after the subvariant was declared a variant of interest that its global risk assessment is low based on available evidence.
Officials have observed some properties of Arcturus being more effective at escaping an immune response than others, but no changes in severity of the virus have been reported in the countries where it has been spreading.
India, where the subvariant is most prominent, and Indonesia have experienced a “slight” increase in hospital bed occupancy, but the levels are notably lower than during previous waves.
But WHO did warn that Arcturus could become dominant in some countries and present more cases because of its “growth advantage” and ability to escape immune responses.
This subvariant might also feature a symptom previously not commonly seen as connected to COVID-19 — conjunctivitis, better known as pink eye.
Some patients have reported experiencing pink eye along with being infected with Arcturus, but doctors are unsure if the symptom is tied to the virus.
The Washington Post reported that anecdotal evidence has pointed to Arcturus causing fever and pink eye, especially in children. Pink eye can be caused by a bacterial or viral infection or by allergies.
The Arizona Republic reported that the American Academy of Ophthalmology said about 1 to 3 percent of patients with COVID-19 have said they have pink eye.
Although the symptom has been observed in some patients, experts have cautioned against conclusions.
Monica Gandhi, a professor of medicine at the University of California at San Francisco, told the Post that “careful study” is needed before declaring a new symptom is linked to a variant.
Neha Narula, a clinical associate professor of medicine at Stanford University, told CBS News that pink eye had been seen in earlier variants but was rare.
“So if you haven’t been protected with the vaccines or boosters, go ahead and get those. But if you are having some of these symptoms, watery eyes, red itchy eyes, or other cold symptoms, especially now with this new sub-variant circulating, don’t write it off as allergies, go ahead and take that Covid test and talk with your healthcare provider so they can give you further guidance in terms of treatment,” Narula said.