Exclusive: Russia's COVID-19 vaccine trial slows as focus shifts to second dose

Russia has temporarily paused the vaccination of new volunteers in its COVID-19 vaccine trial, staff at eight of 25 trial clinics said, with some citing high demand and a shortage of doses. However, the vaccine’s developer said the uptake of new participants had only slowed. At eight of the 25 Moscow clinics hosting the trial and inoculating volunteers, staff told Reuters the vaccination of new participants was temporarily on hold, and several said they had used up the doses allocated to their clinics, referencing a large influx of volunteers.