SARS-CoV genome sequencing to be ramped up

There will be more variants and mutants that could come and the country had enough capacity to carry out genome sequencing and plan public health response based on this, Swarup said.

The Indian SARS-CoV-2 Genomic consortium (INSACOG) has sequenced 15,133 SARS-CoV genome from Covid positive international travellers and from the community samples across states, Dr Sujeet Singh, director, National Centre for Disease Control, said. Variants of the virus have now spread across the country with Punjab reporting the UK variant (B.1.1.7), Maharashtra has seen the Indian (B1.617) variants while Delhi has both the UK variant and the Indian variants prevalent and others are still unfolding. West Bengal is reporting the new triple variant (B.1.618).

INSACOG is a consortium of ten national laboratories, set up by the ministry of health and family welfare and department of biotechnology in January 2021 to monitor the genomic variations in the SARS-CoV-2. To shed light on the second wave and emerging variants and mutants, the department of biotechnology hosted a webinar on Genome sequencing of SARS-Cov-19 on Friday. Dr Renu Swarup, secretary, DB, said during the webinar that they will be scaling up genome sequencing going forward. There will be more variants and mutants that could come and the country had enough capacity to carry out genome sequencing and plan public health response based on this, Swarup said.

There are plans to expand genomic surveillance and five more labs will be joining in. S Das, director, National Institute of Biomedical Genomics, said genome sequencing could be ramped and more sequencing centres could be added but this depended on availability of machines, manpower and supplies. Manpower was getting infected which affected their availability while reagent supplies were issues, Das said. The 5% target set for sequencing in the country was a long way off.

Scientists and public health experts speaking at the webinar said the good news for the country was that both the Indian vaccines – Covshield and Covaxin – were able to offer protection against these mutants. This was based on the preliminary studies carried out by Hyderabad-based Centre for Cellular and Molecular Biology.

Priya Abraham, director, National Institute of Virology, said all these variants were being detected by the RT-PCR tests. The RT-PCR would remain the cornerstone of diagnostics and will continue to be the the gold standard to detect the virus and the variants of every kind. Allaying fears about all the variants, Abraham said a mask can fight every kind of variant and adherence to Covid-appropriate behaviour was needed.

The double mutant Indian variant carries two mutations (L452R and E484Q). The L452R Indian mutant decreased sensitivity to some neutralizing antibodies while E484K/Q reduced efficacy of vaccinated sera and antibodies. The Variants of Concern are the UK variant has it has caused 50% increased transmission and increased severity, South African variant (B.1.351) reduced antibody neutralisation and had 50% increased transmission while the Brazil variant (P.I) reduced neutralisation by antibodies and also reduced neutralisation after vaccination.