President Vladimir Putin announced amid widespread concerns about the rapidly developed vaccine’s safety.

The state-run Gamaleya research institute last week launched Phase III trials of the Covid-19 vaccine involving thousands of volunteers. The Health Ministry has said it plans to begin mass production of the vaccine as soon as next month and launch a mass vaccination drive in October.

“This morning, for the first time in the world, a vaccine against the new coronavirus was registered,” Putin said in a televised cabinet session broadcast.

“I know that it’s effective and forms sustainable immunity,” he said.

Putin said one of his daughters, whose identity he has neither confirmed nor denied to date, has already taken the vaccine.

Its registration certificate on the Health Ministry website notes that the vaccine, an injection solution called “Sputnik-V,” will enter civilian circulation on Jan. 1, 2021.

Experts, including an industry body representing multinationals that conduct clinical trials in Russia, have called the vaccine’s swift registration without completing Phase III trials a “Pandora’s box.”

The World Health Organization last week urged Russia to follow established guidelines and go “through all the stages” necessary to develop a safe vaccine.

Russia has the world’s fourth-highest Covid-19 caseload with almost 900,000 infections.