"Currently, volunteers are being pre-selected to participate in the second stage of the study," the capital's government website said in a statement.
It is noted that a study of the safety of the Sputnik V vaccine for children is underway in Moscow.
In the first stage of the study, 99 minors took part.
Earlier, the director of the Gamaleya National Research Center for Epidemiology and Microbiology, Alexander Gintsburg, said that registration of a children's vaccine against coronavirus is expected soon.