Russian scientists have published the first report on their coronavirus vaccine, saying early tests showed signs of an immune response.
The report published by medical journal The Lancet said every participant developed antibodies to fight the virus and had no serious side effects.
Russia licensed the vaccine for local use in August, the first country to do so and before data had been published.
Experts say the trials were too small to prove effectiveness and safety.
But Moscow has hailed the results as an answer to critics. Some Western experts have raised concerns about the speed of Russia’s work, suggesting that researchers might be cutting corners.
Last month, President Vladimir Putin said the vaccine had passed all the required checks and that one of his own daughters had been given it.