Advancing Needle-Free Jet Injectors for Global Vaccine Delivery

Background: Global immunization programs continue to rely on needle-based injections despite persistent concerns regarding sharps disposal, accidental injuries, and the technical skill required for accurate intradermal administration. Needle-free jet injectors (NFJIs) are an alternative delivery method in which narrow, high-velocity liquid jets penetrate the skin without a needle. Contemporary designs, ranging from single-use disposable-syringe injectors to digitally controlled electromechanical