Sexually transmitted infections represent a recurring and costly burden in populations with persistent exposure, where short-acting therapies and rising antimicrobial resistance limit the effectiveness of today’s treatment-centric approach. In these settings, prevention has clear clinical value and measurable economic impact, yet durable biologic options remain largely unavailable. StiRx is addressing this gap by developing engineered biologics, including monoclonal antibodies, bispecific antibodies, and vaccines designed for long-acting protection at the point of infection. Our strategy is to prevent repeat infection, reduce downstream treatment costs, and give individuals a simple, reliable way to manage ongoing risk.