OBJECTIVE: The purpose of this study was to analyze enrollment of racial/ethnic minorities in Phase I and Phase II HIV vaccine trials in the U.S. conducted by National Institute of Allergy and Infectious Diseases (NIAID)-funded networks from 1988 to 2002. METHODS: A centralized database was searched for all NIAID-funded networks of HIV vaccine trial enrollment data in the U.S. from 1988 through 2002. The authors reviewed data from Phase I or Phase II preventive HIV vaccine trials that included HIV-1 uninfected participants at low to moderate or high risk for HIV infection based on self-reported risk behaviors. Of 66 identified trials, 55 (52 Phase I, 3 Phase II) met selection criteria and were used for analyses. Investigators extracted data on participant demographics using statistical software. RESULTS: A total of 3,731 volunteers enrolled in U.S. NIAID-funded network HIV vaccine trials from 1988 to 2002. Racial/ethnic minority participants represented 17% of the overall enrollment. By pooling data across all NIAID-funded networks from 1988 to 2002, the proportion of racial/ethnic minority participants was significantly greater (Fisher's exact test p-value < 0.001) in Phase II trials (278/1,061 or 26%) than in Phase I trials (347/2,670 or 13%). By generalized estimating equations, the proportion of minorities in Phase I trials increased over time (p = 0.017), indicating a significant increase in racial/ethnic minority participants from 1988 to 2002. CONCLUSIONS: There has been a gradual increase in racial/ethnic minority participation in NIAID-funded network HIV vaccine trials in the U.S. since 1988. In the light of recent efficacy trial results, it is essential to continue to increase the enrollment of diverse populations in HIV vaccine research
