Scientists see downsides to top Covid-19 vaccines from Russia, China

Scientists see downsides to top Covid-19 vaccines from Russia, China CanSino Biologics' vaccine, approved for military use in China, is a modified form of adenovirus type 5, or Ad5. The company is in talks to get emergency approval in several countries before completing large-scale trials, the Wall Street Journal reported last week. https://ift.tt/eA8V8J