For Americans wary of the Johnson & Johnson COVID-19 vaccine as it returns to use after the investigation of a potentially deadly side effect, health experts have a message: The system worked. A recommended hold on the vaccine was lifted on Friday by the U.S. Centers for Disease Control and Prevention and the Food and Drug Administration after a 10-day review of rare and serious blood clots in some people who had received the shot. The small risk of clots from the shot is far outweighed by its protection against the coronavirus, an advisory panel said. In the next six months, the shot could prevent some 1,435 COVID-19 deaths and 2,236 hospitalizations, compared with a projected 26 possible clot cases, according to a presentation by the CDC.