VISAKHAPATNAM: The new Omicron (B.1.1.529) variant of the novel coronavirus seems to be dominating the ongoing third wave of Covid-19 in Andhra Pradesh.
About 85 to 90% of the total samples sequenced in the recent weeks belong to this lineage, which is said to be more transmissible than the earlier forms of the virus.
Officials attribute the high transmissibility and the immune evading behaviour of this variant to the sudden surge in the cases. Within three weeks into the third wave, the daily case positivity rate crossed the peak of the second wave.
Before Omicron, it was virulent Delta (B.1.617.2) that dominated the second wave. As per the available statistics, the change in the landscape of variants of concern might have begun as early as in April 2021.
The Delta variant was found in only 2% of the total sequenced samples in March 2021 in Andhra Pradesh. But the share of Delta cases found in the samples sequenced in April increased to 40% and consequently to 91% in May. Even though the first case of Delta variant was reported back in October 2020 in India, it was detected only in March 2021 in Andhra Pradesh in genome sequencing.
State Covid-19 nodal officer Dr K Rambabu said that whenever a new variant is found, it ideally goes through four stages – VBM (variant being monitored), VOI (variant of interest), VOC (variant of concern), and VOHC (variant of high consequence). “But the B1.1.529 (Omicron) simply jumped the ladder for the World Health Organisation to label it as a VOC,” said Dr Rambabu.
The Union ministry of health and family welfare established the Indian SARS-CoV-2 Consortium on Genomics (INSACOG), a grouping of 10 national laboratories, in December 2020.
INSACOG has since been carrying out genomic sequencing and analysis of circulating Covid-19 viruses, and correlating epidemiological trends with genomic variants.
As per the updated guidelines of the INSACOG on genomic surveillance for SARS-CoV-2, each state is to designate a nodal officer, who will be the focal point for coordination of whole genome sequencing.
