Moderna reported that its mRNA‑1647 cytomegalovirus (CMV) vaccine missed the primary efficacy endpoint in a large Phase III trial and will stop most development of the program. The company said efficacy fell well short of expectations across the seronegative female population targeted to prevent congenital CMV infection. Moderna will reassess its respiratory and vaccine pipeline priorities as the failure intensifies pressure on the company after a challenging year. The setback removes a program that had been forecast as a potential multibillion‑dollar vaccine franchise and forces Moderna to pivot resources toward other assets, including cancer vaccine programs.