A second U.S. company has begun safety tests for a vaccine against COVID-19. The Phase 1 study will enroll up to 40 healthy adult volunteers in Philadelphia and Kansas City, where screening of potential participants has already begun, said the company. The study is a first step to see if the vaccine appears safe enough for further larger tests. Even if the research delivers positive results, it is expected to take over a year before any vaccine is widely available. As of Tuesday night, the number of COVID-19 cases in the United States has topped 390,000, with more than 12,900 deaths.
