Clinical trials target individuals whereas community trials target groups. c. A social intervention targeting HIV prevention is an example of a clinical trial.Clinical trials are research studies that determine if a new drug or medical treatment is safe and effective. Community trials address the efficacy of preventive interventions applied at the group level (e.g. , a social marketing campaign trial). Communitybased clinical trials can help more patients access clinical trials than ever before and make recruitment easier. The key difference is that in community trials the treatments being studied are allocated not to individuals, but to entire communities. Find a Vertex clinical trial. Volunteers who participate in clinical trials help make new medicines a reality. Places, buildings and things look different under the cover of darkness.