Lassa fever

CEPI is one of the world’s leading funders of Lassa fever research. 

Our goal is to support the development of one or more Lassa fever vaccines through to licensure, working with our partners in West Africa and across the world.

Research funded by CEPI and led by the Universities of Oxford and Liverpool and the Liverpool School of Tropical Medicine found that being vaccinated against Lassa fever would prevent millions of people from falling sick with the disease and facing prohibitive treatment costs that could otherwise push them below the poverty line.

Specifically, deploying a safe and effective Lassa fever vaccine across 15 countries of continental West Africa could save nearly 3,300 lives over 10 years and avert up to $128 million in societal costs.

To date, CEPI has invested in six vaccine candidates, three of which remain in active development. 

One of CEPI’s partners, IAVI, launched the first-ever Phase II clinical trial of a Lassa fever vaccine in Nigeria in April 2024. The study has now also launched at sites in Ghana and Liberia.

Later-stage trials are expected to take place in the coming years.

Should candidates be found safe and efficacious in clinical testing, our Lassa fever vaccine developers are committed to making their vaccines affordable and accessible to all populations in need.

To help prepare for the next Disease X, CEPI is also supporting the development of mRNA vaccine candidates with Korean-based company, SK Bioscience. To test SK Bio's rapid-response platform, CEPI's funding is first being used to support the development of an mRNA vaccine against Lassa fever. 

If successful, the vaccine could also be rapidly adapted to help protect against other viruses in the Arenavirus family. 

CEPI created and funds Enable, the world’s largest ever study of Lassa fever set up to give researchers a better picture of the true disease burden. 

Findings from Enable will help us to better understand the number of people who are at risk of Lassa virus infection. 

Over 23,000 participants have taken part across West Africa since 2019. Enable was expanded in October 2024, with a new year-long study that will take an in-depth look at Lassa fever symptoms and potential co-infections like malaria.

Insights gained on the diversity of disease symptoms will enhance our understanding of Lassa fever, categorised into mild, moderate or severe cases. 

This information will be crucial in guiding where and how future late-stage vaccine trials are conducted and determining priority groups for receiving the vaccine once it becomes licensed in the coming years.

Regional leadership is critically important to advance the development of vaccines that protect against the disease. 

CEPI is supporting the new Lassa fever Coalition, a pioneering group established by the West Africa Health Organization (WAHO) to build upon the efforts of national and regional Lassa fever initiatives, and ensure, at a regional level, that those affected by Lassa fever have a safe, effective and high-quality vaccine available to protect their populations in the future.

In January 2025, WAHO in collaboration with Nigeria's Federal Ministry of Health and Social Welfare, hosted the inaugural meeting of the Lassa fever Governing Entity, with support from CEPI. 

The entity will provide country and regional leadership to the Coalition and ensure effective governance and programmatic delivery for vaccine developers, funders, and Member States actively involved in combating Lassa fever. 

Members of the Lassa Governing Entity include Ministers of Health across key Member States including Benin, Guinea, Liberia, Nigeria and Sierra Leone as well as senior representatives from CEPI, WAHO and the World Health Organization Headquarters and Regional Office for Africa (WHO AFRO). 

CEPI has published a Request for Proposals for a Technical Partner to support the set-up of the coalition.

CEPI maintains close engagement with institutions including the Economic Community of West African States (ECOWAS) Regional Centre for Surveillance and Disease Control, as well as national public health agencies, such as the Nigeria Centre for Disease Control (NCDC) and Ministries of Health in the most affected countries. 

CEPI is also coordinating the ECOWAS RegECs Project, a collaboration between regulators, ethics committees and the African Vaccine Regulatory Forum (AVAREF) to support efficient management of clinical research in West Africa. 

The network also aims to create a Lassa fever regulatory and ethics network, using simulation exercises to strengthen regulators' ability to rapidly assess clinical trial dossiers.

CEPI is funding a four-year project led by FIND to examine and evaluate all available point-of-care testing options for Lassa virus as well as Nipah, another CEPI priority pathogen.

High quality diagnostic tests are essential both for early pathogen detection to stop an outbreak and as part of the vaccine development process particularly for the optimal design and conduct of clinical trials.

FIND researchers will identify the criteria for an optimum rapid Lassa diagnostic test and select rapid tests to assess those criteria. Successful diagnostics will be progressed to licensure for widespread use.

In addition to supporting research on Lassa fever vaccine candidates, CEPI is helping build sustainable clinical research capacity in West Africa. 

The project will leverage the infrastructure from the multiple CEPI-funded trials of Lassa fever vaccine candidates to support future outbreaks of other diseases in the region.

CEPI funds a consortium of partners, known as Technical Coordinating Partners (TCP), to lead this effort. This includes International Vaccine Institute (IVI) and MRC Unit The Gambia (MRCG).