AstraZeneca said in December it would start clinical trials to test combining the two vaccines to see if this could boost the efficacy of the British shot. Both vaccines involve two doses, an initial shot and a booster, and use harmless adenoviruses as vehicles, or vectors, to carry genetic instructions into the body to prompt cells to produce antibodies. Sputnik, however, uses different viral vectors for its two shots.
A two-dose regimen of Sputnik V was 91.6% effective against symptomatic Covid-19, according to peer-reviewed late-stage trial results published in the Lancet international medical journal.
Russia is ready to offer a collaboration with Sputnik V to any producer that has a vaccine with efficacy less than 90%, Kirill Dmitriev, the head of Russia’s RDIF sovereign wealth fund, said. Pooled late-stage trial data showed AstraZeneca’s shot was about 70% effective.
“Sputnik was the first in the world to suggest that the two shots should be different to give a stronger and longer immune response, more mutation-proof,” Dmitriev said. “So what others are starting to do with this kind of trial is to follow our steps.”