TWiV examines the claim by Brazil’s ANVISA that the Sputnik vaccine contains replication-competent adenovirus, and a role for the furin cleavage site in SARS-CoV-2 spike for efficient reproduction in the respiratory tract, evasion of antiviral IFITM proteins, and transmission in ferrets.

Daniel Griffin provides a clinical report on COVID-19, review of the phase I and II trials of the Russian prime-boost vaccine, a mouse model that recapitulates age-dependent severe disease, and listener questions.