The fast-changing coronavirus has produced another highly infectious omicron mutant, which caused scientists concern as the new mutant began to develop in India and emerge in many other countries, including the US.
Scientists say the variant – called BA.2.75 – may be able to spread quickly and evade immunity gained from vaccines and previous infections. It is not clear whether this new variant can cause more serious disease than other omicron variants, including the worldwide prominence of BA.5.
“It’s too early for us to draw too many conclusions,” said Matthew Binnicker, director of clinical virology at the Mayo Clinic in Rochester, Minnesota. “But it seems, particularly in India, the transmission rate is showing some sort of exponential increase.” Whether this mutant will have a bigger impact than BA.5, he said, has yet to be determined.
However, the fact that this new mutant has been detected in many parts of the world with even lower levels of virus surveillance “is an early indication that this mutant is spreading,” said Shishi Luo, head of infectious diseases at Helix, the company that supplies virus sequence information to the Centers for Control and Prevention. Disease Prevention America (CDC).
The new mutant has been found in several distant states in India and appears to be spreading more rapidly than the other variants here, said Lipi Thukral, a scientist on the Scientific and Industrial Research Council at the Institute of Genomics and Integrative Biology in New Delhi. It has also been detected early in about 10 other countries, including Australia, Germany, the UK and Canada. Two cases were recently identified on the US west coast, and Helix identified a third case in the US last week.
What sparks experts’ concerns is the sheer number of mutations that separate this new variant from its predecessor omicron. Some of those mutations are in areas associated with protein spikes and could allow the virus to bind to cells more efficiently, Binnicker said.
Another concern is that genetic changes might make it easier for the virus to evade previous antibodies. Antibodies are protective proteins that the body makes in response to a vaccine or infection from a previous variant.
But experts say vaccines and booster is still the best defense to prevent severe illness from COVID-19. In the fall, it is likely that the US will see new formulations of a vaccine developed that target the newer types of omicron. [uh/ab]