Russia on Saturday approved a third coronavirus vaccine for domestic use, Prime Minister Mikhail Mishustin said on state TV, though large-scale clinical trials of the shot, labelled CoviVac and produced by the Chumakov Centre, have yet to begin.

Russia has already approved two COVID-19 vaccines, including the Sputnik V shot, developed by Moscow’s Gamaleya Institute, following a similar approach of granting approval before seeing any late-stage trial results.

The preemptive approvals had raised concerns among some scientists in the West, but inoculations with those first two shots began on a mass scale in Russia only after trials were concluded and showed success, Reuters reported.

Sputnik V was approved in August and late-stage trials began in September. Mass vaccination was launched in December, after preliminary trial results showed the vaccine to be 91.4% effective.

Since then, more than two million Russians have been vaccinated with at least the first dose of Sputnik V, Health Minister Mikhail Murashko said on Feb. 10.

Rollout of a second vaccine, developed by the Vector Institute in Novosibirsk, is beginning.