Addressing global health challenges, particularly in resource-limited settings, requires innovative solutions to overcome barriers such as inadequate infrastructure, restricted patient access, and the complexities of cold chain logistics. In this talk, I will demonstrate how polymers, integrated with advanced engineering design, can drive the development of transformative health technologies. One example is SEAL (StampEd Assembly of polymer Layers), a platform that enables controlled, pulsatile release of biologics over extended periods, offering the potential for single-injection self-boosting vaccines and cancer immunotherapy. Additionally, I will discuss the development of a microneedle vaccine printer, designed to support decentralized production of thermostable COVID-19 mRNA vaccines, broadening vaccine accessibility worldwide.