Mass testing of Russia's first potential Covid-19 vaccine to get domestic regulatory approval will involve more than 40,000 people and will be overseen by a foreign research body when it starts next week, backers of the project said on Thursday.

These were the first details on the shape and size of the upcoming late-stage trial of the vaccine given by its developers, who are aiming to allay concerns among some scientists about the lack of data provided by Russia so far.