The mayor of Moscow invited residents Wednesday to join trials of a coronavirus vaccine that Russia approved for use earlier this month in what officials described as a breakthrough on par with the Soviet Union's launch of the world's first satellite in 1957. The world's first vaccine against the coronavirus to receive a government go-ahead has caused unease among international medical experts, who called Russia's fast-tracked approval and failure to share any data supporting claims of the vaccine's efficacy a major breach of scientific protocol