AP
Many thousands of volunteers from minority groups are needed for huge clinical trials underway or about to begin. Scientists say a diverse group of test subjects is vital to determining whether a vaccine is safe and effective for everyone and instilling broad public confidence in the shots once they become available. The expanded outreach by vaccine researchers and health officials is getting a late start in communities that, because of a history of scientific exploitation and racism, may be the most reluctant to roll up their sleeves. Just getting the word out takes time.