Immunization strategies to prevent malaria in pregnancy – a multistakeholder workshop

As part of the ADVANCE-VAC4PM project, the European Vaccine Initiative (EVI) and La Fondation pour la Recherche Scientifique (FORS) co-hosted a hybrid workshop titled "Strategies for using malaria vaccines to prevent malaria in pregnancy (MiP)". The event brought together researchers, regulators, civil society, global health experts, and policymakers to discuss the need for MiP vaccines and strategies for their development, evaluation, and implementation. Malaria remains a major global health threat, with sub-Saharan Africa bearing the highest burden. Pregnant women (PW) are highly vulnerable, with an estimated 12.4 million affected in 2023. Beyond maternal health effects, a major cause of the MiP-related disease burden is placental malaria (PM), which can cause significant morbidity in newborns. PM risk is greatest in primigravidae and secundigravidae, as immunity develops over successive pregnancies. As existing malaria control strategies remain insufficient, MiP vaccines have the potential to complement them by eliciting immunity comparable to that seen in multigravidae. To be effective, such a vaccine should provide long-lasting immunity and target adolescent girls and women before their first pregnancy. PM vaccine candidates targeting the VAR2CSA antigen (PRIMVAC and PAMVAC) are in development, and existing malaria vaccines preventing infection are being repurposed to prevent MiP. However, limited awareness of MiP-specific burden, weak pharmacovigilance systems, and vaccine hesitancy may hinder future vaccine implementation. Key recommendations highlighted during the workshop included strengthening communication and community engagement strategies, defining relevant efficacy endpoints for pivotal clinical trials, reinforcing pharmacovigilance systems to support safety and real-world effectiveness studies, and planning for early regulatory alignment. Panel discussions emphasized the importance of stakeholder coordination and reduced-dose schedules to support future MiP vaccine programmatic feasibility. The workshop concluded with a call for sustained collaboration and national investment to ensure that MiP vaccines become a viable and effective component of global malaria prevention efforts.