The first large study of the safety and effectiveness of a coronavirus vaccine in the United States began on Monday morning, according to the National Institutes of Health and the biotech company Moderna, which collaborated to develop the vaccine. The study, a Phase 3 clinical trial, will enroll 30,000 healthy people at about 89 sites around the country this summer. Half will receive two shots of the vaccine, 28 days apart, and half will receive two shots of a saltwater placebo. Neither the volunteers nor the medical staff giving the injections will know who will get the real vaccine. And their main goal will be to see if significantly fewer vaccinated people contract Covid-19, to determine whether the vaccine can prevent the illness.

Source: New York Times July 27, 2020 18:33 UTC