Scientists ask: Without trial data, how can we trust Russia’s Covid-19 vaccine?

A researcher at the University of Pittsburgh works on a COVID-19 vaccine candidate, a fingertip-sized patch with dissolvable microscopic needles, in Pittsburgh, Pennsylvania, U.S., March 28, 2020. UPMC/Handout via REUTERS ATTENTION EDITORS – THIS IMAGE WAS PROVIDED BY A THIRD PARTY. MANDATORY CREDIT. NO RESALES. NO ARCHIVES