Omicron's sub-lineage BA.5 increased to 25% in June across TN: DPH

CHENNAI: As Covid cases are again surging in Tamil Nadu, it has been found that the prevalence of BA.5 sub-lineage is 25 per cent, according to revealed by Department of Public Health and Preventive Medicine (DPH).

During the third wave, the whole genomic sequence (WGS) report showed that the majority of cases were Omicron variants. The State Health Department has sent a total of 3,935 samples collected between January and June for WGS and it was found that mutated variants were reported in the last six months.

Of which, from January to March 1,890 samples identified for BA.2, and BA 1.1 with 309 samples. In April, an additional sub-lineage was reported i.e BA.3 identified among 14; 339 samples had BA 2 and two with BA 1.1.

In May 2022, along with BA.2 which was 36 per cent, and BA 2.38 sub-lineage was also detected in 35 per cent of the samples sequenced in Tamil Nadu. In addition, BA.4 with 1.4 per cent and BA.5 was 4 per cent sub-lineages have also been reported.

Currently, BA 2.38 is the predominant Omicron sub-variant reported in May and June (35 per cent) in the state, which has a similar pattern reported in Maharashtra. The circulation of BA.4 is not very significant with only 1.4 per cent in May and 0.2 per cent reported so far in June 2022.

Most importantly, BA.5 has also rapidly increased from 4 percent in May to 25.2 percent in June 2022. This could be the reason for the sudden rise in Covid cases in TN causing symptoms illness.

The State Health Department said that vaccination protects us from severe illnesses and death whatever the variation. Public requested to follow covid appropriate behaviour in addition.