The spread of a new Omicron subvariant has sparked concern in India, the US and elsewhere, as scientists fear the new mutation could bypass immunity to vaccines and previous infections.
However, it is unclear whether this subvariant, designated BA.2.75, could cause more serious diseases than other Omicron variants, including the globally known BA.5.
“It’s very early for us to jump to too many conclusions,” said Matthew Binnicker, director of clinical virology at the Mayo Clinic in Rochester, Minnesota. “But it looks like transmission rates, particularly in India, are showing some sort of exponential increase.”
It hasn’t been decided yet if it will surpass BA.5, he added.
The fact that the variant was spotted in parts of the world with less virus surveillance “is an early sign that it’s spreading rapidly,” warns Shishi Lou, head of infectious diseases at Helix, a company that provides virus sequencing information the US Centers for Disease Control and Prevention.
The latest mutation of Covid-19 has been detected in several different states in India and appears to be spreading faster than other variants, said Lipi Thukral, a scientist at the Council of Scientific and Industrial Research-Institute of Genomic and Integrative Biology.
So far it has been reported in several Indian states including Kerala, Tamil Nadu, Karnataka, Andhra Pradesh, Telangana, Uttar Pradesh, Maharashtra and the state capital Delhi.
It has also been detected in 10 other countries including the United States, Australia, Germany, the United Kingdom and Canada.
Some of the mutations in the new variant are related to the receptor-binding domain of the spike protein, said WHO chief scientist Dr. Soumya Swaminathan.
“Since this is the key part of the virus that has attached itself to the human receptor, we need to keep an eye on its behavior. But it’s too early to tell if the subvariant has additional immune invasion characteristics or is clinically more severe,” she said Indian times.
The scientists, working with the Indian Sars-CoV-2 Genomics Consortium (Insacog), a genome surveillance agency under the Indian Ministry of Health, said those infected with BA.2.75 were either asymptomatic or had mild Covid, adding, that they had not yet observed possible infection clusters of the subvariant.
Researchers said vaccines and boosters are the best defense against infection.
“Some may say, ‘Well, vaccinations and boosters haven’t stopped people from getting infected.’ And yes, that’s true,” said Dr. binnicker
“But we have seen that the number of people who end up in hospital and die has decreased significantly. As more people have been vaccinated, boosted or infected naturally, we are beginning to see background levels of immunity increasing around the world.”
Additional reporting by agencies