Epidemiology and Vaccine Efficacy of Delta Variant

Abstract

Several variants of concern (VOCs) of SARS-CoV-2 have emerged after its first outbreak in 2020. These VOCs possess mutations in the spike protein that confers enhanced rate of infection and transmission of these VOCs. Among these VOCs, the delta/B.1.617.2 variant was identified in late 2020 in India and soon spread to several countries around the globe. Currently, it is the most widely sequenced variant among new infected individuals with SARS-CoV-2 infection. This variant is also found to be associated with COVID-19 infection in vaccinated individuals, but the severity of disease and rate of hospitalization are low among these individuals as compared to unvaccinated individuals. With the emergence of new variants of SARS-CoV-2 due to continuous mutations, it is suggested that vaccination plays a significant role in preventing the transmission of disease and disease severity.