Data from the global genome sequence repository GISAID appears to indicate that the Omicron sub-lineage BA.2 drove the third wave of the pandemic, at least for the states from where genotyping data has been shared routinely.

As per genome sequencing data submitted by Indian laboratories to the GISAID database, over half of the cases in the last month may have been due to the BA.2 sub-lineage, revealed an analysis on outbreak.info. A detailed analysis of Indian data on GISAID by molecular biologist, Bijaya Dhakal, from Texas, indicates that cases in several states were dominated by BA.2. The major states where the trend is clear include Delhi, Uttar Pradesh, Karnataka and Gujarat.

In Delhi, the shift from BA.1 and BA.1.1 to BA.2 seems to have occurred at the end of December. One of the most updated sequencing data came from Gujarat, where BA.2 became dominant from around the second week of January, revealed the GISAID data… (HT, January 31, 2022)