One case of SARS COV-2 Omicron Variant – BA.4 Sub Lineage has been reported In Tamil Nadu based on the initial whole genomic sequencing report. The officials from the State Public Health Laboratory, Chennai confirmed the same but the result from other laboratories under the Indian SARS-CoV-2 Consortium on Genomics (INSACOG) is awaited.
As per the current testing protocol, community clusters, family clusters, re-infection, children, and samples from severely ill patients were prioritized for whole genomic sequencing to look for the emergence of new variants.
A release from the Directorate of Public Health and Preventive Medicine said that the clusters at IIT Madras and Sri Sathya Sai Medical College were due to BA.2 variant of Omicron only. A total of 3,328 samples have been subjected to sequencing from January to May 2022 and 96 percent of the variants belongs to Omicron only. BA.2 is the predominant variant reported in 73 percent of the samples sequenced. BA.1 sub-lineages are also being reported to some extent in Tamil Nadu.
Recently, one case of BA.4 was reported in Tamil Nadu. The sample of 19-year-old female from a family of four, including father, mother, daughter and grandmother residing in a gated community at Navalur, OMR had the BA.4 subvariant.