1.1 Sponsored satellite session: How to prepare for and prevent outbreaks of Viral Hemorrhagic Fevers: advances in vaccine development

Organiser: IAVI, Netherlands

Viral hemorrhagic fevers (VHFs) caused by pathogens such as Lassa virus (LASV), Sudan ebolavirus (SUDV), and Marburg virus (MARV) pose a significant and growing threat to public health across sub-Saharan Africa. Characterised by high case fatality rates—ranging from 15–20% for Lassa to over 50% for filoviruses such as Sudan and Marburg—these diseases often emerge without warning and can overwhelm fragile health systems. Outbreaks occurring as recently as 2025, including Uganda’s sixth SUDV outbreak and Tanzania’s second MARV outbreak in two years, underscore the increasing frequency of these diseases. Despite their severity, countermeasure availability remains limited: there are no licensed vaccines for LASV, SUDV, or MARV, and access to investigational tools is often delayed by challenges in coordination, manufacturing, and clinical infrastructure.

This session will bring together experts leading cutting-edge vaccine development efforts to address these three high-priority pathogens through integrated approaches that span epidemiology, rapid clinical trial deployment, vaccine candidate advancement, and innovative partnership models. We will explore real-time data and lessons from the 2025 Ebola Sudan outbreak response in Uganda, new preclinical and clinical results for VSV-based vaccines against LASV, SUDV, and , MARV, and discuss how novel collaborations—especially those prioritizing local and regional clinical trial networks and manufacturing—can accelerate end-to-end product development for outbreak-prone diseases.

The session will feature four focused talks followed by an extended audience discussion, offering participants a holistic understanding of how future responses to VHF outbreaks can be faster, more coordinated, and better prepared.