Background: Pandemic preparedness and response (as with all public health actions) occur within a social, cultural, and historical context of preexisting health disparities and, in some populations, underlying mistrust in government. Almost 200,000 people received H1N1 vaccine at 109 free, public mass vaccination clinics operated by the Los Angeles County Department of Public Health between October 23, 2009, and December 8, 2009. Wide racial/ethnic disparities in vaccination rates were observed with African Americans having the lowest rate followed by whites.
Methodology/principal findings: Demographic information, including race/ethnicity, was obtained for 163 087 of the Los Angeles County residents who received vaccine. This information was compared with estimates of the Los Angeles County population distribution by race/ethnicity. Rate ratios of vaccination were as follows: white, reference; African American, 0.5; Asian, 3.2; Hispanic, 1.5; Native American, 1.9; and Pacific Islander, 4.3.
Significance: Significant political challenges and media coverage focused on equity in vaccination access specifically in the African American population. An important challenge was community-level informal messaging that ran counter to the "official" messages. Finally, we present a partnership strategy, developed in response to the challenges, to improve outreach and build trust and engagement with African Americans in Los Angeles County.