School-Located Vaccination to Reduce Inequities in Vaccination Uptake Among Historically Excluded Populations in Colorado - Health disparity populations are more likely to face barriers to immunization in traditional medical settings. Specifically, people from minoritized racial/ethnic groups, residents of underserved rural areas, and households with less advantaged socio-economic status are more likely to lack a primary care medical home, report logistical challenges accessing medical offices (e.g., lack of transportation, clinic hours, long wait times), and live in areas with poor access to primary care. Prior to the COVID-19 pandemic, school-located vaccination (SLV) had been successfully used for routine and pandemic (H1N1) vaccines to overcome some of these access barriers. SLV can occur through School-Based Health Centers (SBHCs) or School-Located Vaccine Clinics (SLVCs). SLVCs are time-limited events focused on the mass delivery of one or more vaccines. They can be led by a school nurse, coordinated through an SBHC, if available, or conducted in partnership with local health systems or health departments. As only 13% of public school students in the United States had access to an SBHC in the 2016-17 school year, SLVCs play an important role in extending the reach of SLV. Recently, schools gained substantial experience with SLVCs due to the urgency of the pediatric COVID-19 vaccine roll-out. Because most SBHCs are located in urban, low-income, and racially/ethnically minoritized communities and SLVCs typically provide vaccines free of cost to all students regardless of insurance status, they are often assumed to improve health equity. However, there have been no systematic investigations of the full scope of SLV models (SBHCs, SLVCs independent of an SBHC, and SLVCs run by SBHCs) to determine whether locating vaccination services in schools increases immunization rates in health disparity populations. To fill this critical gap, this study will apply quasi-experimental methods, microsimulation modeling, and a modified positive deviance approach grounded in implementation science to examine the impact of the three models of SLV (SBHCs, SLVCs, and both) on routine, influenza, and COVID- 19 vaccination rates among school-aged children in Colorado, overall and for health disparity populations. We aim to: (1) Describe SLV models (SBHCs, SLVCs, and both) in Colorado from 2018-2024, the local context in which they were implemented, and how model and school characteristics changed over time; (2) Estimate causal impacts of SLV models on routine, influenza, and COVID-19 vaccine uptake among school-aged children (5-17 years) from 2018-2024; (3) Simulate potential local- and state-level impacts of SLVCs on routine, influenza, and COVID-19 vaccine coverage among all students in Colorado and members of health disparity populations; and (4) Qualitatively investigate contextual barriers to and facilitators of recent SLV implementation in Colorado. Study findings will be immediately actionable for SLV implementers and policymakers seeking to reduce vaccination disparities among school-aged children and adolescents.
