U.S. biotechnology company Moderna Inc. said Monday it has started a final-stage clinical trial of a potential coronavirus vaccine that would involve 30,000 participants across the country.The Massachusetts-based firm reported earlier this month in a U.S. medical journal that the experimental vaccine proved generally safe and provoked immune responses in all 45 participants in an early-stage test, without any serious side effects observed.Testing for the latest trial will take place at around 89 clinical research sites in the United States, according to the National Institutes of Health, which…
