The UK Health Service Agency (UKHSA) has designated a sub-variant of Omicron as a “variant under investigation”, saying that it is a level below the status of Omicron, marked a “variant of concern” by the WHO.
The stealth omicron is “a sub-lineage known as BA.2 of the dominant and highly transmissible Omicron coronavirus variant”, said Dr Mrinal Sircar, director oof Pulmonology and critical care at Fortis Hospital, Noida. “As per UKHSA, 40 countries had reported BA.2 sequences, with the most in Denmark, followed by India, Britain, Sweden and Singapore,” the expert added.
While the BA.2 strain is being attributed to faster infection, doctors dismiss the possibility of it being a more severe strain than the present Omicron variant. “So far, there is insufficient evidence to determine whether BA.2 causes more severe illness than Omicron BA.1, but data is limited. For now, what we know is that the BA.2 case severity is comparable to classic variant Omicron cases. Also, there is likely to be minimal differences in vaccine effectiveness against BA.1 and BA.2,” Dr Sircar told indianexpress.com.
Agreed Dr Laxman Jessani, Consultant, Infectious Diseases, Apollo Hospitals Navi Mumbai, said that “In India we are already seeing this substrain in our genomic testing. The symptoms and treatment are same as other substrains, like BA.1. Also, the vaccine efficacy of BA.2 is also same as other sub variants.”
Both the experts confirmed that while the sub variant doesn’t escape an RT-PCR test, “the way the variant was confirmed was by seeing if there was a S gene drop out for BA.1. In BA.2, there is no S gene drop out, it would be difficult to confirm if it is BA.2 or some other variant without a full genome sequencing,” stated Dr Sircar.
Answering if the new variant is of concern, where it has already been detected amidst rising Covid-19 cases, Dr Sircar said, “A greater spread of any virus means potentially more mutations, which holds true for this variant as well.”