The purpose of this toolkit is to help local health department (LHD) staff prepare for future influenza A pandemics by practicing their assessment and implementation skills each year during seasonal influenza. A public health infectious disease emergency response, such as a mass vaccination campaign, will be more effective if we understand the changing needs, attitudes, beliefs, and behaviors of our diverse communities. Because these characteristics can differ significantly by age group, gender, ethnicity, income level, or neighborhood, we can use this knowledge to customize our response.