In this handout photo taken on Thursday, Aug. 6, 2020, and provided by Russian Direct Investment Fund, a new vaccine is on display at the Nikolai Gamaleya National Center of Epidemiology and Microbiology in Moscow, Russia.
Scientists around the world say any widely-used vaccine should first be tested in advanced trials involving tens of thousands of people to prove it is safe and effective before being licensed.
In his invitation to the Russian capital's residents, Moscow Mayor Sergei Sobyanin appeared to announce those kind of broad studies would be launched soon.
Sobyanin encouraged Moscow residents to sign up, arguing that the vaccine was based on longtime previous research and proven to be safe.
Last month, the U.S., Britain and Canada accused Russia of using hackers to steal vaccine research from Western labs.