Russia has dismissed mounting international concern over the safety of its locally developed Covid-19 vaccine as "absolutely groundless".
On Monday, it said a vaccine had been given regulatory approval after less than two months of testing on humans.
But experts were quick to raise concerns about the speed of Russia's work, and a growing list of countries have expressed scepticism.
BBC News reports scientists in Germany, France, Spain, and the US have all urged caution.
The first packages of the vaccine. will be received within the next two weeks, primarily for doctors.
Russian officials have said they plan to start mass vaccination in October.
Russia's President Vladimir Putin has also said the vaccine had passed all the required checks and his daughter had already been given it.
But the World Health Organization said it was in talks with Russian authorities about undertaking a review of the vaccine, which has been named Sputnik-V.
It is not among the organisation's list of six vaccines that have reached phase three clinical trials, which involve more widespread testing in humans.
[Source: BBC]
