Russia has developed the first vaccine offering "sustainable immunity" against the coronavirus after less than two months of human testing, President Vladimir Putin claimed on Tuesday.
"This morning, for the first time in the world, a vaccine against the new coronavirus was registered" in Russia, he said during a televised video conference call with government ministers.
The development paves the way for the mass inoculation of the Russian population, even as the final stage of clinical trials to test safety and efficacy continue.
The speed at which Russia is moving to roll out its vaccine highlights its determination to win the global race for an effective product, but has stirred concerns that it may be putting national prestige before sound science and safety.
Addressing a government meeting on state television, Mr Putin said the vaccine, developed by Moscow's Gamaleya Institute, was safe and that it had even been administered to one of his daughters.
"I know that it works quite effectively, forms strong immunity, and I repeat, it has passed all the needed checks," he said, and expressed hope the country would soon start mass producing the vaccine.
Its approval by Russia's health ministry foreshadows the start of a larger trial involving thousands of participants, commonly known as a Phase III trial.
Such trials, which require a certain rate of participants catching the virus to observe the vaccine's effect, are normally considered essential precursors for a vaccine to receive regulatory approval.
Regulators around the world have insisted that the rush to develop a Covid-19 vaccine would not compromise safety. But recent surveys show growing public distrust in governments' efforts to produce rapidly such a vaccine.
Russian health workers treating Covid-19 patients will be offered the chance of volunteering to be vaccinated soon after the vaccine's approval, a source told Reuters last month.
More than 100 possible vaccines are being developed around the world to try to stop the Covid-19 pandemic. At least four are in final Phase III human trials, according to data from the World Health Organisation.