Denis Logunov and colleagues1 report their interim results from a phase 3 trial of
the Sputnik V COVID-19 vaccine in The Lancet. The trial results show a consistent
strong protective effect across all participant age groups. Also known as Gam-COVID-Vac,
the vaccine uses a heterologous recombinant adenovirus approach using adenovirus 26
(Ad26) and adenovirus 5 (Ad5) as vectors for the expression of the severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) spike protein. The use of two varying serotypes,
which are given 21 days apart, is intended to overcome any pre-existing adenovirus
immunity in the population.