Moscow said on Thursday it would start clinical trials on more than 40,000 people early next week for its coronavirus vaccine, which the Russian authorities approved on August 11.

Last week, President Vladimir Putin said Russia, as the first in the world, licensed the coronavirus vaccine, drawing scepticism in the West because the vaccine did not pass the necessary extended clinical trials before licensing, required to prove its effectiveness.

“Next week, a clinical study of the effectiveness and safety of the Sputnik V vaccine will begin in Russia,” in 45 medical centres, the Russian Sovereign Fund involved in developing the vaccine said.

The official website publishing information about the vaccine reported that “the third phase of clinical trials involving more than 2,000 people” began in several countries on August 12.

The Fund said that the Russian law did not stipulate the third phase.

“From a legal point of view, these are studies conducted after the registration of the vaccine on August 11,” the Fund said, adding the testing could be considered “equivalent to phase three”.

The head of the Fund, Kirill Dmitriev, told an online briefing on Thursday the voluntary vaccination of “risk groups”, including the medical staff, would also start next week.

He added that more than 20 countries had already applied for the purchase of a billion doses of Russian vaccine.

Dimitriev also said that Moscow agreed on the production of the vaccine in five countries, and expected the beginning of mass vaccinations in Russia in October.

The distribution of the vaccine abroad is planned for November or December.

The Sputnik V vaccine rose some eyebrows in the West primarily due to the lack of a final phase of testing at the time it was licenced.

Dimitrijev said Russia did not see any problem that individual regulatory bodies approve the vaccine even without the consent of the World Health Organization (WHO).

In the meantime, WHO Office for Europe said it had begun talks with Russia to learn more about the experimental COVID-19 vaccine.