Moscow began distributing the Sputnik V COVID-19 shot via 70 clinics on Saturday. It marks Russia's first mass vaccination against the disease, the city's coronavirus task force said. Though final trials have yet to be completed, for Sputnik V or a second vaccine. And scientists have raised concerns about the speed at which Russia has worked, giving the regulatory go-ahead for its vaccines and launching mass vaccinations before safety and efficacy have been fully tested. The task force said the Russian-made vaccine would first be made available to doctors and other medical workers, teachers and social workers because they ran the highest risk of exposure to the disease. Moscow, the epicenter of Russia's coronavirus outbreak, registered 7,993 new cases overnight, well above the daily tallies of around 700 seen in early September. The age for those receiving shots is capped at 60. People with certain underlying health conditions, pregnant women and those who have had a respiratory illness for the past two weeks are barred from vaccination. Russia has developed two COVID-19 vaccines, Sputnik V, which is backed by the Russian Direct Investment Fund and another developed by Siberia's Vector Institute. The Sputnik V vaccine is administered in two injections, with the second dose expected to be given 21 days after the first.