The think is Russia may have taken the quick route of human challenge trials and already know that the vaccine they have is effective.
Take a few hundred subjects, randomly divide them into treatment (who get the vaccine) and control (who get saline injections), wait a few weeks, expose the lot of them to the disease and see how many fewer and how much milder the cases among the treatment group are compared to the controls. No waiting for a sample of 30,000 similarly divided to be naturally exposed to the virus over the course of months, which is what Phase III trials in the West consist of. It's contrary to Western medical ethics developed since the exposure of the Tuskegee experiments, but it quickly verifies the efficacy. It's also arguable that if the subjects are volunteers (might or might not have been the case if the Russians went that way, probably wasn't when the Chinese almost certainly did -- they'd have used Uighur prisoners or Falun Gong practitioners) that under the conditions of a pandemic of a lethal illness, it is, in fact, ethical to take accept the altruistic impulse of the volunteers, and offer them the best medical care available for several years after participation as compensation for their participation (which would also minimize the fatalities and other adverse consequences to the volunteers).