Abuja: The ENABLE 1.5 Lassa Research Programme has been underway in West Africa to explore the connection between Lassa fever and malaria, as well as to assess community readiness for upcoming vaccines. This study is crucial in addressing key gaps in the understanding of these health issues.
According to News Agency of Nigeria, the study is funded by the Coalition for Epidemic Preparedness Innovations (CEPI) and began in late 2024. It is set to run until mid-2026 across Liberia, Nigeria, and Sierra Leone, with the aim of achieving significant scientific and public health objectives. The prospective cohort study involves 5,000 participants, with at least 1,000 individuals per site being closely monitored for a year to measure the incidence of the Lassa virus, malaria co-infection, and long-term complications, such as permanent hearing loss.
This phase of the study builds upon ENABLE 1.0 (2021-2023), which included over 23,000 participants from Benin, Guinea, Liberia, Nigeria, and Sierra Leone. It provided important data on Lassa virus exposure and distribution patterns. The earlier phase recorded an overall Lassa virus seroprevalence of about 30 percent, with Edo State, Nigeria, reporting the highest incidence rate of 1.9 cases per 1,000 persons in surveillance findings. It also highlighted that children are as vulnerable to Lassa fever as adults.
The study indicates that mild cases are often missed, and the rates of malaria coinfection in Lassa patients remain poorly studied, necessitating targeted data gathering and analysis. ENABLE 1.5 aims to determine symptomatic infection rates confirmed by RT-PCR testing, measure malaria co-infection among Lassa patients, and assess sensorineural hearing loss incidence in survivors to inform vaccine trials and health interventions.
The study will also evaluate community perceptions of Lassa vaccination and willingness to join future clinical trials. By using participatory approaches, the study aims to improve acceptance and build trust within targeted populations. To reduce participant dropout, researchers plan to involve community health workers and survivors as advocates, alongside sensitization campaigns on rodent control, environmental sanitation, and insecticide-treated mosquito net usage in high-risk communities.
Communities from ENABLE 1.0 will receive updates on past findings, ensuring transparency and strengthening local relationships, while random household selection in Lassa hotspots will ensure a balanced representation across five age categories. Participants will undergo regular check-ups, blood tests, and hearing assessments. Suspected cases will be tested for both diseases, and confirmed cases will be promptly referred to treatment centers following national health guidelines. Survivors will be followed for months to monitor recovery progress, detect delayed complications, and collect valuable information about the long-term health and socioeconomic impact of the disease on affected individuals.
NAN recalls that Lassa fever is an acute viral hemorrhagic illness mainly spread by contact with infected rodent urine or droppings. Severe cases can cause multi-organ failure, with fatality rates reaching 70 percent. Although historically peaking during dry seasons, recent trends suggest year-round transmission in Nigeria, Liberia, and Sierra Leone, potentially driven by climate change, urbanization, and other evolving socio-environmental factors influencing disease patterns.
CEPI has stated that ENABLE 1.5 will generate robust evidence for late-stage vaccine trials, inform delivery strategies, and strengthen regional outbreak preparedness and response for Lassa fever and associated health challenges. By understanding the true burden, including mild cases and pediatric infections, interventions can be better targeted, and preparations for the introduction of future vaccines can be more effective.
The findings are expected to shape West Africa’s response to a disease that has persisted for decades, ensuring that when vaccines become available, communities will accept and benefit from them.
