In an attempt to expand its infectious disease portfolio, Pfizer has agreed to acquire respiratory syncytial virus (RSV) drug developer, ReViral, for a total consideration of up to US$525 M. With the deal, Pfizer gains access to ReViral’s Phase III lead asset sisunatovir, an oral inhibitor designed to block fusion of the RSV to the host cell. The acquisition aligns with Pfizer’s commitment to treating the common infection, as its own RSV vaccine programme recently received multiple FDA designations and clinical advancements.