The two-dose Sputnik vaccine was 91.6% effective at preventing symptomatic COVID-19 and 100% effective at preventing severe and moderate disease in a study involving 19,866 participants.
The data were published in The Lancet. No data, however, was available on the impact of SARS-CoV-2 variants on the vaccine’s efficacy.
By comparison, the single-dose JNJ vaccine was 57% to 72% effective at preventing moderate to severe disease, depending on the geography. The vaccine was least effective in South Africa, where 95% of infections were the result of a more-infectious variant circulating there.
AstraZeneca’s (LON:AZN) two-dose vaccine was between 62% and 90% effective, depending on the dosing regimen.
The organization that developed the vaccine, the Gameleya Institute, has experience developing vaccines for Ebola, MERS and smallpox.
Like those from AstraZeneca and Johnson & Johnson, its vaccine is adenovirus-vectored. The Sputnik V vaccine, however, is novel in its use of two separate adenovirus vectors. The first dose of the vaccine uses adenovirus-26, which is the same variant Johnson & Johnson uses in their vaccine. The second dose uses adenovirus-5, a commonly used viral vector used in clinical research.
CanSinoBIO-Beijing Institute of Biotechnology is also experimenting with an adenovirus-5-based vaccine.
Gameleya Institute scientists have also experimented with AstraZeneca’s non-replicating chimpanzee adenovirus for one of the doses.