Nigerian Participants Receive First Phase 2 Lassa Fever Vaccine in IAVI-Backed Trial

In a significant advancement for global health, a Phase 2 clinical trial for a Lassa fever vaccine has commenced in Nigeria. The initiative is led by IAVI, a non-profit scientific research organization, and is sponsored by CEPI, a global partnership focused on accelerating vaccine development against epidemic and pandemic threats.

Lassa fever, a deadly hemorrhagic disease prevalent in West Africa, currently lacks an approved vaccine. The disease has a significant impact, with an estimated 5,000 deaths and around 300,000 illnesses annually across West Africa. The virus poses a considerable threat, particularly to children under 10, pregnant individuals, and healthcare workers.

The trial involves a vaccine candidate developed by IAVI, which has demonstrated promising results in Phase 1 trials, showing good tolerability and the ability to stimulate an immune response. The Phase 2 study will further assess the vaccine's safety, tolerability, and immunogenicity at different dosage levels in a diverse group of participants, including adults, adolescents, and children over two years old. The trial is expected to enroll approximately 612 participants across Nigeria, Ghana, Liberia, and potentially other regions, subject to regulatory approvals.

Dr. Abdulwasiu Bolaji Tiamiyu, the principal investigator of the trial in Nigeria, emphasized the importance of local collaboration, stating that Nigerian clinicians, scientists, and community members play a crucial role in ensuring that the vaccine development process is informed by local context and experience.

The need for a Lassa fever vaccine is underscored by the ongoing outbreaks of the disease and the emergence of Ebola Sudan in Uganda. The development of vaccines for known disease threats is vital for preparedness during outbreak situations. IAVI's vaccine candidate uses a recombinant vesicular stomatitis virus (rVSV) vector platform, similar to the one used in ERVEBO®, a single-dose Zaire ebolavirus vaccine licensed in several countries.

The goal of IAVI and CEPI is to ensure global equitable access to vaccines. If the Lassa fever vaccine candidate proves safe and effective, IAVI is committed to making it affordable and accessible to populations in need. The vaccine candidate's development and testing are part of IAVI's broader strategy to address emerging infectious disease threats, which includes routine immunization and stockpiling vaccines for rapid deployment during larger outbreaks.

The results of the Phase 2 trial are anticipated in 2025 and will be disseminated through open-access publications and scientific meetings to benefit the wider scientific and medical community. The collaboration between IAVI, CEPI, and regional partners is a significant step towards managing and preventing Lassa fever outbreaks and enhancing global health security.