Genome sequencing: No new VOC/sub-lineage of Omicron found

The Health Department has received genome sequencing reports of 513 RTPCR samples (whose CT levels were less than 25) in November. The good news is that no new sub-lineage of Omicron or no new ‘variant of concern (VOC)’ of Covid was found in the samples.

Covid Technical Advisory Committee chairperson Dr M K Sudarshan said that only a new novel VOC that is immuno-evasive can trigger another Covid wave (as all Covid restrictions removed everywhere, except in China).

“This is because about 90 per cent of us have immunity to Omicron and other old variants of Covid detected in the state either due to vaccine or infection (symptomatic or asymptomatic or both) based on age and comorbidities. Covid-19 paediatric sero survey conducted in June this year among children between 6 years to 14 years of age, had indicated that 75% of surveyed children had anti-Covid antibodies,” said Dr Sudarshan.

INSACOG (Indian SARS Cov2 Genomics consortium) has confirmed that in the samples sent in November, it is found that, ETA/kappa/pango variants of Covid dominated and they were found in 296 samples. Sub-lineages of the Omicron variant of Covid declined in November and were found in 217 samples.

Sub-lineages of the Omicron variant of Covid, BA2 has been confirmed in 197 samples; BA5 is confirmed in 20 samples.

Dr Sudarshan said that the variants found in these cases are mild. The Health Department is doing genome sequencing of Covid positive samples with CT values below 25 among symptomatic international arrivals, those hospitalised or from large clusters with more than five cases or wherever there is an outbreak with more than 15 cases. Five to 10 per cent of Covid positive samples are considered for genome sequencing.