This comparative analysis explores HIV prevention, PrEP (pre-exposure prophylaxis), and health equity across two critical border regions: San Diego–Tijuana and Brownsville–Matamoros. These binational corridors reflect unique public health dynamics shaped by migration, resource allocation, stigma, and cross-border collaboration. While San Diego and Brownsville benefit from robust U.S. public health infrastructure, their Mexican counterparts often face limitations in consistent access to HIV testing, PrEP availability, and stigma-free services.

Despite these disparities, both border regions exhibit innovative grassroots efforts, mobile outreach, and binational cooperation. By examining existing models and challenges—including policy misalignment, funding gaps, and the mobility of at-risk populations—this study identifies key strategies for ending the HIV epidemic. These include enhancing cross-border referral systems, expanding culturally competent PrEP education, leveraging shared data, and supporting community-led navigation programs. As infectious diseases recognize no borders, regional collaboration and equity-driven policies are essential to closing gaps in prevention and ensuring no community is left behind in the fight against HIV.