Economic value of vaccinating geographically hard-to-reach populations with measles vaccine: A modeling application in Kenya.

BACKGROUND: Since special efforts are necessary to vaccinate people living far from fixed vaccination posts, decision makers are interested in knowing the economic value of such efforts. METHODS: Using our immunization geospatial information system platform and a measles compartment model, we quantified the health and economic value of a 2-dose measles immunization outreach strategy for children <24 months of age in Kenya who are geographically hard-to-reach (i.e., those living outside a specified catchment radius from fixed vaccination posts, which served as a proxy for access to services). FINDINGS: When geographically hard-to-reach children were not vaccinated, there were 1427 total measles cases from 2016 to 2020, resulting in $9.5 million ($3.1-$18.1 million) in direct medical costs and productivity losses and 7504 (3338-12,903) disability-adjusted life years (DALYs). The outreach strategy cost $76 ($23-$142)/DALY averted (compared to no outreach) when 25% of geographically hard-to-reach children received MCV1, $122 ($40-$226)/DALY averted when 50% received MCV1, and $274 ($123-$478)/DALY averted when 100% received MCV1. CONCLUSION: Outreach vaccination among geographically hard-to-reach populations was highly cost-effective in a wide variety of scenarios, offering support for investment in an effective outreach vaccination strategy.