The Delta variant is now replacing all other SARS-CoV-2 variants. We found a mean R0 of 5.08, which is much higher than the R0 of the ancestral strain of 2.79. Rapidly ramping up vaccine coverage rates while enhancing public health and social measures is now even more urgent and important.
Keywords: Alpha variant; B1.617.2; COVID-19; Delta variant; R0; SARS-CoV-2; Wuhan; basic reproductive number; epidemic potential; pandemic; transmissibility; variants of concerns.