Nigerian Scientists Expand Research Into Deadly Lassa Fever

Scientists in Nigeria are expanding their research into the deadly Lassa fever with the launch of a pioneering study designed to get a better idea of the variation in disease symptoms and how these compare to malaria and other worrisome infections found in the region.

The new research, led by the Nigeria Centre for Disease Control and local study sites, forms part of Enable, the world’s largest Lassa fever study.

Enable was created by the Coalition for Epidemic Preparedness Innovations (CEPI) and partners to provide a more accurate picture of the disease burden in West Africa and help inform outbreak preparedness efforts, including the development of a Lassa vaccine.

The Coordinating Minister of Health and Social Welfare, Dr Muhammad Ali Pate who noted that Lassa fever remains a public health burden in Nigeria and West Africa said the commitment to research and innovation was yielding promising progress.

” The new Enable research will deepen our understanding of the virus and enhance the work being undertaken to develop the first-ever Lassa vaccine to safeguard the health of our communities. The Federal Ministry of Health and Social Welfare remains committed to working alongside our partners and neighbouring nations to advance these efforts and bring the suffering caused by Lassa fever to an end.”

Five thousand healthy people, including children and infants, will be invited to take part in the new year-long study. The research will launch this month at sites in Nigeria (Edo, Ondo and Ebonyi states), as well as Sierra Leone and Liberia in later weeks.

While Lassa fever is a known public health burden in the region—with hundreds of thousands estimated to be infected each year—many cases are likely going unreported due to difficulties with Lassa case detection.

The new research therefore aims to improve scientific understanding on how commonly Lassa fever occurs, how rates of infection and symptoms vary across selected locations, ages, sex and previous exposure to the virus, and the extent of post-infection symptoms like hearing loss. Scientists will also look at how often people may be co-infected with Lassa fever and malaria since co-infections may complicate the clinical course of each disease.

A recent modelling study, led by the Universities of Oxford and Liverpool and the Liverpool School of Tropical Medicine and funded by CEPI, estimated that 3300 lives could be saved across the region over a ten-year period from the introduction of a Lassa vaccine. The most advanced Lassa vaccine candidate is currently undergoing Phase 2 trials in the region.

The Enable National Project Coordinator, Mrs Elsie Ilori, , said: “The launch of this expanded Lassa fever study is a key step in our ongoing efforts to understand and combat this dreadful disease.

On his part, the Director General of Nigeria Centre for Disease Control and co-chair of the Nigeria Lassa Vaccine Task Force, Dr Jide Idris,   said: “This expanded investigation represents key progress in our battle against Lassa fever.

First formally diagnosed in Nigeria in 1969, Lassa fever is a potentially deadly disease primarily spread to people by infected Mastomys rats. While the majority of those infected are thought to be asymptomatic, it can lead to more serious symptoms, including in mother and baby if pregnant women become infected. On average 1% of cases are fatal. The World Health Organization has identified Lassa fever as a priority pathogen in urgent need of R&D.

CEPI first launched Enable in 2019. Over 23,000 participants across West Africa have taken part in the research to date, with initial data collected up to 2024 expected to published in upcoming months.

In addition to increasing knowledge of the disease and its case count across the region, Enable is advancing study site capabilities and helping them prepare for future epidemic and vaccine research, such as potentially supporting future Lassa vaccine trials.

PR