Lassa Fever Vaccine Candidate Progresses in Phase 2 Study

The International AIDS Vaccine Initiative (IAVI) recently announced that clinical trial sites in the Lassa fever-endemic countries of Ghana, Liberia, and Nigeria were vaccinating volunteers in IAVI's C105 study of a Lassa fever vaccine candidate.

This study is designed to evaluate the vaccine candidate’s safety, tolerability, and immunogenicity at two different dosage levels in adults, including people living with HIV, as well as in adolescents and children two years of age and older. 

The IAVI C105 study results are expected in 2025. Should the vaccine candidate be found safe and efficacious, IAVI is committed to making its Lassa vaccine affordable and accessible to all needy populations.

As of August 28, 2024, no Lassa fever vaccine currently exists. However, several vaccine candidates are conducting research.

Lassa virus (LASV) is a zoonotic disease that causes the acute viral hemorrhagic illness called Lassa fever, for which treatment is limited.

People can get Lassa fever by contacting infected rats or their saliva, urine, or droppings. The U.S. CDC says that LASV can spread among people.

About 300,000 people fall ill across West Africa annually, though the actual disease burden is thought to be much higher. For these reasons, Lassa fever is featured in the World Health Organization’s R&D Blueprint and requires urgent action due to its potential to cause an outbreak of international concern.