PregInPoxVac

Mpox is a viral disease transmitted through close contact. Although often mild, it can lead to severe illness and high mortality, particularly among vulnerable populations such as pregnant people and young children. In the Democratic Republic of the Congo (DRC) – the epicentre of the 2024 outbreak – children account for 40% of reported mpox cases. 

Despite their increased risk, access to the MVA-BN vaccine against mpox remains extremely limited for pregnant people and young children. 

Maternal and infant safety and immunogenicity in a phase 3, open-label, randomised, vaccine trial of a two-dose Mpox vaccine

PregInPoxVac is a collaboration between the University of Antwerp, the University of Kinshasa, Fondazione Penta ETS and Africa Clinical Research Management Limited. 

The project involves a Phase 3 vaccine trial in Boende, DRC, evaluating the safety and immunogenicity of the MVA-BN vaccine in two high-risk groups: 

• Healthy pregnant and postpartum people (aged 16-35), with a two-dose vaccine regimen 
• Infants and children aged 6-24 months, comparing a full dose versus half-dose vaccine regimen. 

Since November 2023, mpox cases have surged across Central and West Africa, especially in the DRC. In August 2024, the World Health Organization declared mpox a Public Health Emergency of International Concern due to a sharp increase in Clade 1 cases in the region. 

Preliminary data suggest the MVA-BN vaccine is safe for pregnant people and likely poses no risk to breastfed infants. However, robust data in vulnerable populations is still lacking. Furthermore, infants and children, because of their developing immune systems, may respond differently to vaccines compared to adults. Therefore, conducting vaccine trials in real-world, high-risk environments is essential for evaluating both safety and effectiveness. 

Vaccine hesitancy, fuelled by misinformation and healthcare system distrust, remains a major barrier – especially among pregnant people. Addressing these concerns through tailored communication and community engagement is critical to improving vaccine uptake. 

Alongside the clinical trial, Penta will conduct a series of qualitative activities aimed at investigating the perceptions, attitudes and experiences of pregnant people and families of infants and children regarding Mpox vaccination and involvement in vaccine trials. Penta will also assess stakeholder perspectives on mpox vaccination and participation in vaccine trials among pregnant and post-partum people, as well as parents or legal guardians of infants and young children. 

The project is funded by the Global Health EDCTP3 and its members (project No. 101195533) and the Coalition for Epidemic Preparedness Innovations (CEPI).