Moderna disclosed that its mRNA‑1647 cytomegalovirus (CMV) vaccine failed to meet the primary efficacy endpoint in the Phase III CMVictory trial in seronegative females aged 16–40. The company said the shot showed limited efficacy and will pause the pivotal development program for CMV prevention in its current form. Moderna characterized the result as a setback but emphasized ongoing efforts to pivot resources to other vaccine and oncology programs in its pipeline. The readout has implications for mRNA vaccine development beyond SARS‑CoV‑2 and raises questions about antigen selection and immune correlates for congenital CMV prevention.