Bavarian Nordic A/S reported positive topline results from a clinical study of its MVA-BN mpox/smallpox vaccine in pediatric populations, demonstrating that children aged 2-11 years achieved non-inferior immune responses compared to adults while maintaining a comparable safety profile. The findings represent a significant advancement in addressing mpox vaccination gaps among vulnerable pediatric populations, particularly in Africa where the disease remains a declared continental health emergency.
Enhanced Immune Response in Pediatric Population
The study (NCT06549530) enrolled 460 individuals across two cohorts: children aged 2-11 years and adults aged 18-50 years, with the primary objective of comparing safety and immunogenicity of two standard doses of MVA-BN vaccine between these populations. Conducted at sites in the Democratic Republic of Congo and Uganda with co-funding from the Coalition for Epidemic Preparedness Innovations (CEPI), the study evaluated 451 individuals for the primary endpoint.
Results showed that children (n=227) demonstrated immune responses two weeks after the second vaccination that were non-inferior to the adult group (n=224). Notably, the immune response in children was 2.5 times higher than in adults as measured by neutralizing antibody titers, with the highest immune responses observed in the youngest subgroup of children aged 2-5 years.
Safety Profile and Regulatory Pathway
The vaccine was generally well tolerated in the pediatric population, with a safety profile similar to adults and no unexpected signals. Safety and immunogenicity data generated from adults in this study were comparable to historical MVA-BN data, providing additional validation of the vaccine's established profile.
Pending final study results, Bavarian Nordic plans to submit data to the European Medicines Agency (EMA) in 2026 to support an extension of the vaccine's approval to include children aged 2 years and older. MVA-BN is currently approved by the European Commission for individuals aged 12 years and older.
Addressing Critical Public Health Needs
Paul Chaplin, President & CEO of Bavarian Nordic, emphasized the significance of these findings: "Mpox remains a major public health threat, particularly in Africa, where the disease is widespread. While vaccination efforts have significantly improved, certain populations remain highly vulnerable, including younger children. With the support from CEPI and local partners in Africa, we have now shown MVA-BN to be well-tolerated and to generate a robust and clinically relevant immune response in this population, bringing us one step closer to approval of our vaccine for children aged 2-11 years."
Nina Wressnigg, Head of Clinical Development Science at CEPI, highlighted the urgent need for expanded pediatric access: "Mpox has been raging across Africa for over a year and remains a declared continental health emergency. Although MVA-BN has been licensed for emergency use in children in the Democratic Republic of the Congo - the worst affected country - many other countries lack this access causing children to continue to bear the brunt of the suffering, marked by severe illness and possible loss of life."
Current Vaccine Status and Market Position
MVA-BN (Modified Vaccinia Ankara-Bavarian Nordic) is the only non-replicating mpox vaccine approved in multiple jurisdictions, including the U.S. (marketed as JYNNEOS), Canada (IMVAMUNE), and the EU/EAA and United Kingdom (IMVANEX). Originally developed as a smallpox vaccine in collaboration with the U.S. government, MVA-BN was designed to ensure vaccine supply for the entire population, including immunocompromised individuals who cannot receive traditional replicating smallpox vaccines.
The findings could expand vaccine access to children in countries severely affected by the current mpox outbreak surging in Africa, with cases also reported globally. This development represents a critical step toward comprehensive outbreak control and protection of vulnerable pediatric populations who have been disproportionately affected by severe illness and mortality from mpox infection.
