Cost-effectiveness of a behavioral insights-informed digital campaign to increase HPV vaccination in Bangladesh.

Digital platforms like social media are increasingly used to promote vaccine uptake in low- and middle-income countries (LMICs), yet limited evidence exists on their economic value. This study estimates the cost-effectiveness of a behavioral insights-informed social media campaign designed to increase HPV vaccine uptake among adolescent girls ages 9-14 in Bangladesh. A static cost-effectiveness analysis was conducted from the health system perspective. Inputs included campaign delivery costs, vaccine procurement and distribution, and treatment costs averted through cervical cancer prevention. Disability-adjusted life years (DALYs) averted per vaccinated girl were modeled using global burden-of-disease parameters. Effectiveness estimates were drawn from a quasi-experimental evaluation of the campaign, which reported a 9.5 percentage-point increase in vaccine uptake in one study arm and a 5.3 percentage-point increase in another, relative to a control group. These findings were preceded by a posttest study in Dhaka Division, which showed a strong association between campaign exposure and vaccination behavior. The incremental cost per vaccinated girl was $6.02, and the cost per DALY averted - i.e. the Incremental Cost-Effectiveness Ratio (ICER) - was $39.57. This falls well below established cost-effectiveness thresholds, including 40% of GDP per capita, commonly applied in LMICs. The findings suggest that digital campaigns guided by behavioral insights can represent a highly cost-effective approach to addressing persistent immunization coverage gaps. These results support the integration of such strategies into national immunization programs, particularly in contexts where traditional outreach methods may face financial constraints.