Safety and immunogenicity of Ervebo® and Zabdeno® booster vaccines against Ebola virus following previous vaccination with the Zabdeno®/Mvabea® or Ervebo® vaccine schedules in DRC: a mix-and-match phase II RCT

EBO-BOOST aims to address the ongoing challenge of Ebola Virus Disease (EVD), which remains a significant public health concern in West and Central Africa, particularly in the Democratic Republic of Congo (DRC). Despite available therapeutics and two licensed vaccines, EVD outbreaks continue to pose a lethal threat. Because the long-term efficacy and immunological waning of the vaccines outside of an acute outbreak setting have not been properly studied, EBO-BOOST aims to (i) assess the long-term persistence and quality of immune responses in previously vaccinated individuals with Zabdeno/Mvabea® and Ervebo® in DRC, and (ii) answer the question whether these previously vaccinated persons can be safely and adequately boosted with homologous and heterologous booster schedules. This research will guide policy decisions and recommendations on re-vaccination strategies.