10pc 3rd wave cases in Tamil Nadu that of Omicron subvariant: Experts

While several reports and experts report Omicron subvariant BA.2 as dangerous due to higher severity as the delta variant and related complications, state health department officials stated that the third wave saw at least 10 per cent of the BA.2 sub-variant of Omicron in Tamil Nadu. So far, the severity levels of BA.1 and BA.2 in TN have not shown a major difference, but experts stress vaccination and following safety measures.

The genomic sequencing reports of samples collected during the third wave had revealed that the highest number of cases of COVID-19 were BA.1.1 variant of Omicron, which was about 51 per cent, while Omicron variant BA.1 comprised 37 per cent of the total cases. A total of 10 per cent were BA.2 subvariant of Omicron, while Delta was about 2 per cent.

“Even though reported in several other States, in Tamil Nadu, the severity of the cases did not differ much among Omicron subvariants. As of now, we do not see any major cause of concern. However, we should not let our guard down. As more than 1 crore people are yet to get vaccinated with the second dose, we should concentrate on that,” said Dr J Radhakrishnan.

Experts said the Omicron variants BA.1 and BA.2 are similar to each other with respect to mutational behaviour and the BA.2 variant of Omicron is not completely new for us as it has been detected in India in the third wave. Both the variants have higher transmissibility and there are some studies stating that BA.2 might be severe but we have not seen any difference in mortality or prevalence,” said Dr R Ebineser, Senior Consultant and Head, Critical Care Medicine, Apollo Speciality Hospital Vanagaram.

“We might have seen just 10 per cent as per records, it could be more than that as the genomic sequencing was not done for all the cases. The mortality was low in the third wave and we do not anticipate any concern. Several countries are seeing more cases of COVID-19, but there can be individual factors,” he added.

Senior virologist Dr Jacob John said the third wave has come to an end and there is less probability that Omicron variants will have more severity and lead to another wave.