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 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, four of which remain in active development. 

One of CEPI’s partners, IAVI, launched the first-ever Phase II clinical trial of a Lassa 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 vaccine developers are committed to making their vaccines affordable and accessible to all populations in need.

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 and who might benefit from Lassa fever vaccination. 

Over 23,000 participants have taken part across West Africa since 2019. To add to the research, in October 2024, CEPI expanded Enable with a new year-long study that will take an in-depth look at Lassa 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 Lassa vaccine once it becomes licensed in the coming years.

Regional and national leadership from Lassa-affected countries are critically important to advance the development of vaccines that protect against the disease. 

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 also supports or acts as an observer for country-level Lassa vaccine coalitions in Nigeria, Liberia and Sierra Leone, and is helping to bring affected countries and partners together in a locally anchored and regionally led Lassa Coalition to align on the end-to-end development and delivery of a Lassa vaccine. CEPI has published a Request for Proposals for a Technical Partner to support the set-up of the regional Lassa coalition convened by the West Africa Health Organization (WAHO).

CEPI is also coordinating the ECOWAS RegECs Project, a collaboration between regulators, ethics committees, and the African Vaccine Regulatory Forum (AVAREF) network to support efficient management of clinical research in West Africa and to create a Lassa disease-related regulatory and ethics network, using simulation exercises to strengthen regulators' ability to rapidly assess clinical trial dossiers based on risk-benefit analysis.

CEPI is funding a four-year project led by FIND to examine and evaluate all available point-of-care testing options for Lassa 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 ongoing research on Lassa vaccine candidates, we are investing substantially in enabling science activities that shall support a sustainable research framework in the affected countries.

One of these activities is a CEPI-funded effort to build sustainable clinical research capacity in West Africa, leveraging funded infrastructure for multiple trials of Lassa fever vaccine candidates and even future outbreaks of any other disease in the region.

To achieve this ambitious goal, CEPI funds a consortium of highly-experienced partners, known as Technical Coordinating Partners (TCP) including International Vaccine Institute (IVI) and MRC Unit The Gambia (MRCG) to facilitate the work across West Africa.