Reducing vaccine disparities for the urban underserved
Vaccination rates for U.S. immigrant populations have long been lower than those of U.S.-born citizens, a pattern that continued to hold true in the first years of the COVID-19 pandemic. Even as diverse drivers of vaccine hesitancy are increasingly understood and addressed, vaccination rates against a number of diseases among immigrant communities remain lower. Intervention attempts to encourage vaccination have historically focused on individual actions and behaviors, rather than addressing systemic and structural barriers to vaccine access.
To better understand the persistent systemic and structural barriers that continue to impede vaccination uptake among underserved BIPOC communities in urban settings, the University of Washington’s Population Health Initiative and the Somali Health Board led a mixed-methods, community-based participatory research study. This study sought to identify and document systemic and structural barriers to accessibility that continue to negatively impact vaccination rates among Black and African immigrant communities, even after sustained campaigns (during COVID-19) effectively and significantly reduced vaccine hesitancy and increased access in these populations.
The project, which ended in July 2025, had three key research objectives:
- Measure changes in immunization rates over the last eight years among Black and African immigrant populations in King County, Washington, to identify key vaccine preventable diseases where immunization rates lag behind those of non-Hispanic White populations, and/or where rates lag behind those now achieved for COVID-19 in the target population.
- Identify key systemic and structural barriers to vaccine accessibility among specific urban populations in King County.
- Identify key mitigation strategies that reduce the negative impact of the most significant barriers to vaccine access and uptake.
Major findings from the study included:
- Before COVID-19, vaccination disparities between Black and White populations were already growing, signaling that inequities in access and uptake were well established. The pandemic widened these gaps further. Rates for COVID-19, flu and routine vaccines declined, driven by inconsistent public health guidance, unclear messaging about the purpose and effectiveness of booster doses, relaxed workplace mandates and widespread misinformation.
- Misinformation was a major driver of hesitancy. It extended skepticism beyond COVID-19 to other immunizations and intensified long-standing community concerns—such as Somali participants’ fears around the perceived link between the MMR vaccine and autism.
- Participants emphasized the need for clear, accessible education—not only about vaccine safety and side effects, but also about how vaccines work, why they are recommended and the scientific research supports them. They recommended delivering this information in plain language, across multiple and engaging platforms and in ways that reflect cultural and linguistic diversity.
- Building trust requires early and sustained community engagement, responsiveness to community priorities and improved access and visibility of vaccine opportunities. It also means working with trusted messengers and community leaders, increasing diversity with the healthcare workforce and reinforcing the importance of vaccines through strong provider recommendations and public health policies.
- Results also point to the need for upstream approaches to vaccination policy that address broader structural barriers such as housing instability, food insecurity, lack of paid time off, transportation and childcare.
Our research offers recommendations to boost vaccination rates and reduce racial disparities among Black and African immigrant communities in King County, guiding policy, funding, program standards and community partnerships.
The project team included faculty and staff from the UW Department of Global Health, Institute for Health Metrics and Evaluation and the Population Health Initiative, as well as staff and leaders from the Somali Health Board.
Funding Acknowledgement
This study was funded by a research grant from the Investigator-Initiated Studies Program of Merck Sharp & Dohme Corp (MISP Reference Number 102172).