This review summarizes the literature on SARS-CoV-2 variants, focusing on their transmissibility, antigenicity, mutations (spike protein furin cleavage site and non-spike proteins), recombination, and evolution in the context of T cells, innate immunity, and population immunity. The interplay between virus biology and human immunity (vaccination and prior infection) significantly impacts the fitness of VOCs. The relationship between virus antigenicity, transmission, and virulence is complex and has unpredictable implications for COVID-19's future trajectory.

Alessandro M Carabelli, Thomas P Peacock, Lucy G Thorne, William T Harvey, Joseph Hughes, Sharon J Peacock, Wendy S Barclay, Thushan I De Silva, Greg J Towers, David L Robertson