Evaluation of Demographic and Clinical Characteristics of First, Second, and Third Coronavirus Disease 2019 Pandemic Waves in India

Maharashtra in late 2020 or early 2021 and has since expanded throughout India. 7,8 High transmissibility, high virulence, and decreased effectiveness of control measures were seen with the B.1.617variant.As a result, WHO announced it as a variant of concern and finally named it "Delta" (Pango lineage B.1.617.2). 9 It was observed that the Delta mutant, or the B.1.617.2 lineage, subsequently transformed into a new strain known as the "Delta plus" or "AY.1" variety during the third wave of the COVID pandemic.The newly mutated Delta plus variant was first found in India in April 2021 and had three mutations in the spike protein (K417N, V70F, and W258L), and one mutation in ORF1 (A1146T). 10One of the important mutations found in the Delta plus variant, K417N,