A top US epidemiologist has asked WHO to declare BA.2 sub-strain of the Omicron variant of the coronavirus as a ‘variant of concern’ (VoC) after a laboratory study conducted in Japan revealed that it is ‘not only faster at spreading, but also likely to cause more severe disease.
“It is now 100% clear that the @WHO needs to declare #Ba2 a high risk “variant of concern”. Dear @mvankerkhove @doctorsoumya @DrTedros @gabbystern @DrMikeRyan — please make it so. VOC declaration of BA2 now ASAP (sic),” Dr. Eric Feigl-Ding, a top US epidemiologist tweeted.
Maria Van Kerkhove, the Covid-19 technical lead at WHO, said: “BA.2 is already a VOC. It is Omicron.”
He asserted so on the basis of a study by a Japanese team led by researchers from the University of Tokyo, which revealed that similar to BA.1, BA.2 subvariant of Omicron appears to largely escape the immunity induced by Covid-19 vaccines.
It was discovered that the ones infected with BA.2 got sicker and developed a worse lung infection. This was evident from tissues samples, as researchers found the lungs of hamsters infected with BA.2 to be more damaged than those that got BA.1.
From neutralization experiments, the team found that this latest subvariant, first detected in February this year in countries such as Denmark and the UK, is resistant to antibodies, developed from vaccination against Covid-19. This feature is present in the original Omicron as well.
BA.2 was found resistant to the antibodies in people who were infected with the earlier variants of SARS-CoV-2, and ‘almost completely resistant’ to some monoclonal antibody treatments used to treat this disease.
Researchers from the University of Tokyo that similar to BA.1, BA.2 subvariant of Omicron appears to largely escape the immunity induced by Covid-19 vaccines.
“Neutralisation experiments show that the vaccine-induced humoral immunity fails to function against BA.2 like BA.1,” the authors of the study said.
Omicron was first reported from Botswana and South Africa in November 2021. Its BA.1 sub-variant has since rapidly spread across the world and outcompeted other variants such as Delta.
Last week, the World Health Organization (WHO) announced that though BA.2 is more transmissible than BA.1, it is not more severe.