Statement from the National CMV Foundation on Moderna's mRNA-1647 Phase 3 Trial Results

Today's news that Moderna's investigational CMV vaccine did not achieve its intended outcomes represents a disappointment for the field of CMV vaccine research and prevention. The congenital CMV (cCMV) community—families, clinicians, and scientists alike—has been hopeful for a successful vaccine trial after decades of dedicated work.

We extend our deep gratitude to Moderna for their vision, commitment, and courage in taking on this challenge. Their leadership in advancing CMV vaccine development and their ongoing partnership in advocacy have brought much-needed attention to a virus that affects tens of thousands of infants and families each year. Their efforts have moved the field forward in meaningful ways, even as we await detailed data from this trial to inform the next generation of vaccine candidates.

While vaccine development remains an important component of our efforts to eliminate congenital CMV, it is not the only path forward. CMV continues to be a leading cause of birth defects, hearing loss, and neurodevelopmental disability worldwide. Our commitment to the other vital pillars of CMV prevention remains stronger than ever: raising public awareness, promoting evidence-based education about CMV transmission and behavioral prevention strategies during pregnancy, implementing universal newborn screening to ensure early identification and intervention, and advancing research on safer and more effective antiviral treatments.

Dr. Mark Schleiss, Professor of Pediatric Infectious Diseases at the University of Minnesota and Director of our Scientific Advisory Committee, shared his thoughts: "Although these results are not what would have been hoped for, Moderna deserves credit for their transparency in sharing the results of a successfully completed phase 3 study—a substantial accomplishment. Additional data analysis will inform and direct future vaccine studies, which are needed. In the meantime, we must remember that we have many tools that can help prevent cCMV infection. Women of childbearing age can talk to their doctors, learn about prevention, recognize risk factors, and ask about screening. Promoting education about the risks of CMV in pregnancy—all of these approaches will help reduce cCMV, even as vaccine research continues."

Dr. Sallie Permar, Chair of the Department of Pediatrics at Weill Cornell Medical School, also shared her perspective: "This outcome, while a setback, is further informing our understanding of immune protection against this virus. Science moves forward through both success and failure, and this is why continued investment in research—and in building the pipeline of scientists committed to understanding and preventing CMV—is essential. The hope for a future vaccine remains alive, and scientists, pediatricians, OBs, and advocates are steadfast in our commitment to a CMV vaccine that will eliminate a major cause of lifelong disabilities in children."

We also call on the pharmaceutical and biotechnology sectors to continue investing in innovative antiviral and immunologic approaches. The need remains urgent, the science is advancing, and the CMV community stands ready to partner in every way possible to protect the health and futures of all children.

Together, we remain steadfast in our mission to eliminate the devastating impact of congenital CMV.