Genomic Profiling of Sars-Cov-2 Strains Circulating in South Eastern Region of India During Three Waves of Pandemic

Abstract

Continuous bio-surveillance of SARS-CoV-2 is an ongoing task at local, national and global levels since the pandemic onset for understanding genetic evolution and vaccine efficacy. Present study was designed to track the emergence of new variants along the duration of three peaks of infection in the city of Puducherry, India. A total of 128 samples were subjected to Illumina deep RNA sequencing. The results showed predominance of uncommon, delta and omicron variants in first, second and third waves respectively. The most common pangolin lineage was B.1.560 and B.1.617.2. The study observed a total of 3133 common and 11 new mutations. The most common is in the Spike_D614G. A new set of mutations was observed in key viral factors such as NS16 that are implicated to be involved in immune evasion. This may have impact on enhanced disease virulence, vaccine efficiency and possible tolerance to current antivirals. This warrants further in vitro studies to understand the significance of the mutations. While the results presented would also augment the ongoing research on evolutionary and the genetic epidemiology of SARS-CoV-2, it also emphasizes the need for continuous genetic monitoring to predict the forthcoming threats due to the emergence of new or existing variants.