Bavarian Nordic has initiated the first clinical trials designed to evaluate its MVA-BN mpox vaccine in two of the most vulnerable populations: infants under 2 years of age and pregnant and breastfeeding women. The Danish vaccine company announced that the first participants have been vaccinated in these landmark studies, which could potentially expand access to mpox vaccination for high-risk groups currently without approved protection options.
Dual Studies Target Critical Vulnerable Populations
The first study (NCT06844487) is evaluating the safety and immunogenicity of MVA-BN in 344 infants aged 4-24 months, with vaccination of initial participants already underway. Simultaneously, recruitment has begun for a second study (NCT06844500) planned to enroll 359 pregnant or breastfeeding women, also assessing safety and immunogenicity parameters.
Both trials are being conducted in the Democratic Republic of Congo (DRC), which serves as the epicenter of the ongoing mpox outbreak. This geographic focus is strategically important, as infants and pregnant women in this region remain highly vulnerable to mpox infection.
"Through partnerships we have made significant advances already by expanding access to our mpox vaccine for children and adolescents," said Paul Chaplin, President & CEO of Bavarian Nordic. "These new studies will fill the gap by providing important data about the use of MVA-BN in infants and pregnant women, and we applaud the study partners as well as the funding partners, EDCTP3 and CEPI for supporting this important work which could help support a label expansion for MVA-BN to include the most vulnerable populations."
Multi-Partner Research Initiative
The studies form part of the PregInPoxVac research project, led collaboratively by the University of Antwerp and the University of Kinshasa. The international research consortium includes additional partners from Kenya (ACE Research) and Italy (Penta Foundation), demonstrating the global commitment to addressing mpox vaccination gaps in vulnerable populations.
Funding for this comprehensive research initiative comes from multiple sources, including the European Union Global Health EDCTP3, the Coalition for Epidemic Preparedness Innovations (CEPI), and Bavarian Nordic itself.
Expanding Pediatric Coverage
Beyond the infant and maternal studies, Bavarian Nordic is simultaneously sponsoring a trial of MVA-BN in children aged 2-11 years, which has received funding support from CEPI. Topline results from this pediatric trial (NCT06549530) are anticipated in the third quarter of 2025. Once full results become available, these data could potentially support regulatory approval of MVA-BN for younger children, further expanding the vaccine's approved age range.
Current Vaccine Status and Regulatory Landscape
MVA-BN, or Modified Vaccinia Ankara-Bavarian Nordic, represents the only non-replicating mpox vaccine currently approved across multiple jurisdictions. The vaccine has received regulatory approval in the United States, Switzerland, Singapore and Mexico (marketed as JYNNEOS), Canada (marketed as IMVAMUNE), and the European Union/European Economic Area and United Kingdom (marketed as 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 vaccine is currently indicated for use in the general population among individuals considered at risk for smallpox or mpox infection.
The successful completion of these trials could represent a significant advancement in mpox prevention strategies, potentially providing the first approved vaccination option for infants and pregnant women facing mpox exposure risks. Given the ongoing outbreak dynamics in the DRC and the particular vulnerability of these populations, the clinical data generated from these studies may prove crucial for public health response efforts in affected regions.
