The origin of COVID-19 pandemic, caused by SARS-CoV-2, was traced to Wuhan, China. Thereafter, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) evolved into various variants owing to genome-wide mutations, causing emergence of multiple variants, including Variant of Interest and Variant of Concern. Here, we discuss genomic architecture of SARS-CoV-2, as well as its multiple variants- alpha, beta, gamma, and delta, along with their biological properties, such as transmissibility, reduction in antibody-mediated neutralization, virulence, disease severity, vaccine effectiveness, and the prevalence across the India vis-à-vis world. Our data on VOC, pooled from the Global Initiative on Sharing All Influenza Data up to 31 October 2021, shows around 89% prevalence of delta VOC across various Indian States. Whereas alpha, beta, and gamma variants show 10.44%, 0.57%, and 0.11% prevalence, respectively. Compared with global scale, the reported Indian prevalence of alpha, beta, gamma, and delta are 0.40%, 0.63%, 0.04%, and 1.7%, respectively. Furthermore, prevalent vaccines of various natures show significantly reduced effectiveness against these VOCs, necessitating urgent need for development of effective prophylactic vaccines and potential therapy to contain the pandemic.
