Russia has become the first country to approve a COVID-19 vaccine.
The move was met with international skepticism, with scientists around the world alarmed that it cut corners.
The Russians skipped Phase 3 trials, which take several months and involve tens of thousands of people.
But President Vladimir Putin says the vaccine underwent the necessary tests and offers a lasting immunity from COVID-19, noting that one of his adult daughters was inoculated.
Scientists in Russia and other countries say a rush to start using the vaccine could backfire.
Russia has reported more than 890,000 cases of COVID-19, the fourth-highest total in the world.
According to a Johns Hopkins University tally, total confirmed cases of COVID-19 around the world has surpassed 20 million.