Omicron sub-variant BA.5 may be the reason for the sudden rise in COVID-19 cases in Tamil Nadu. From only 4% in May, the sub-variant was identified in 25.2% of SARS-CoV-2 samples sent for whole genomic sequencing so far in June.
Data released by the Directorate of Public Health and Preventive Medicine on the emergence of BA.2.38 and BA.5 sub-variants in May-June 2022 showed that BA.5 was the third highest sub-variant identified in the samples sequenced in June so far. While the BA.2.38 Omicron sub-variant took the top spot as it was identified in about 35% of samples, BA.2, which has been in circulation for a while now, was reported in 26.9% samples.
In May, along with BA.2 Omicron sub-lineage, which was identified in 36% of samples, BA.2.38 sub-lineage was detected in nearly 35% of the samples sequenced in the State. In addition, BA.4 was reported in 1.4% of samples and BA.5 in 4% of the samples.
Currently, the BA.2.38 sub-variant is the predominant Omicron variant reported in the State. A similar pattern was reported from Maharashtra as well.
However, what was more significant was the rapid increase in the BA.5 sub-variant. This could be the reason for the sudden rise in COVID-19 cases in the State, causing symptomatic illness, the Health Department noted. Based on the findings, it stated that the circulation of BA.4 was not very significant in the State.
Health Secretary P. Senthilkumar said there was an increase in the BA.5 sub-variant. “So, our basic weapon remains mask, hand hygiene, physical distancing and vaccination,” he said.
T.S. Selvavinayagam, Director of Public Health and Preventive Medicine, added, “Vaccination protects us from severe illness and death whatever be the variant. In addition, we need to follow COVID-19 appropriate behaviour,” he said.
A total of 3,935 samples were sequenced from January to June in the State.