Moderna announced that its Phase III CMV vaccine, mRNA‑1647, missed the primary efficacy endpoint and the company will stop further development of the shot for most populations. The pivotal CMVictory study failed to prevent congenital cytomegalovirus infection in seronegative women ages 16–40, prompting management to reallocate resources away from the program. The readout compounds pressure on Moderna after earlier pipeline setbacks and follows broader debate about mRNA vaccine applications beyond infectious disease.