RUSSIA (CBS) -- Russia on Tuesday became the first country to clear a coronavirus vaccine and declare it ready for use, despite international skepticism.

President Vladimir Putin said that one of his daughters has already been inoculated.

Putin emphasized that the vaccine underwent the necessary tests and has proven efficient, offering a lasting immunity from the coronavirus.

However, scientists at home and abroad have been sounding the alarm that the rush to start using the vaccine before Phase 3 trials - which normally last for months and involve thousands of people - could backfire.

Speaking at a government meeting Tuesday, Putin said that the vaccine has undergone proper testing and is safe.

The Health Ministry said in Tuesday’s statement that the vaccine is expected to provide immunity from the coronavirus for up to two years.

Putin emphasized that vaccination will be voluntary,

Russian authorities have said that medical workers, teachers and other risk groups will be the first to be inoculated. Deputy Prime Minister Tatyana Golikova said that the vaccination of doctors could start as early as this month.

Professor Alexander Gintsburg, head of the Gamaleya Institute that developed the vaccine, said that vaccination will start while the Phase 3 trials continue. He said that initially there will be only enough doses to conduct vaccination in 10-15 of Russia’s 85 regions, according to the Interfax news agency.

Russian officials have said that large-scale production of the vaccine will start in September, and mass vaccination may begin as early as October.

Russia has registered 897,599 coronavirus cases, including 15,131 deaths.

The World Health Organization said all vaccine candidates should go through full stages of testing before being rolled out.

Experts have warned that vaccines that are not properly tested can cause harm in many ways - from a negative impact on health to creating a false sense of security or undermining trust in vaccinations.