Hope Rises for Single Lassa Fever Vaccine

The search for a lasting solution to Lassa fever has taken a promising turn, as health experts now believe that similarities among different strains of the virus across West Africa could make it possible to develop a single vaccine that would work effectively throughout the region. This optimism was shared by Professor Alash’le Abimiku, the Executive Director of the International Centre of Excellence, during an interview ahead of the Institute of Human Virology Nigeria’s annual scientific symposium in Abuja.

Professor Abimiku explained that the centre has been deeply involved in studies that focus on both the Lassa virus and the rodents responsible for transmitting it to humans. These studies, conducted across different states including Bauchi and Edo, aimed to track whether the strains of the virus varied significantly from one region to another. Findings so far suggest that although the Lassa virus undergoes minor mutations, the strains circulating within Nigeria and across West Africa are largely similar. For scientists, this is a significant discovery because it indicates that a single vaccine could potentially cut across different regions, offering broad protection against the disease.

Lassa fever has long been one of Nigeria’s most persistent public health challenges. The disease is an acute viral hemorrhagic illness caused by the Lassa virus and is primarily spread through contact with food or household items contaminated by the urine or feces of infected rats. Human-to-human transmission is also possible, especially in healthcare settings when infection control measures are inadequate. According to the Nigeria Centre for Disease Control and Prevention, symptoms usually start with fever, weakness, sore throat, and headaches. In severe cases, patients may experience chest pain, nausea, vomiting, and in some instances, bleeding from the gums, nose, or internal organs. The disease is endemic in many Nigerian states, with Edo, Ondo, and Bauchi consistently recording some of the highest case numbers each year. Fatality rates among hospitalised patients can range between 15 and 20 per cent, making it one of the deadliest infectious diseases in the country.

The possibility of a single vaccine is particularly encouraging for Nigeria and the rest of West Africa. The region continues to bear the brunt of recurring outbreaks, which put immense pressure on healthcare systems and leave communities vulnerable year after year. Current statistics from the NCDC reveal that Nigeria has already recorded 857 confirmed cases of Lassa fever in 2025, with 160 deaths reported by late August. This represents a fatality rate of 18.7 per cent, which is higher than the 17.1 per cent recorded during the same period in 2024. Outbreaks have been reported in 21 states across 106 local government areas, with Ondo, Bauchi, Edo, Taraba, and Ebonyi alone accounting for 90 per cent of all infections. The most affected age group remains young adults between the ages of 21 and 30, a demographic that makes up much of Nigeria’s active workforce.

Professor Abimiku revealed that several candidate vaccines are already undergoing trials across parts of West Africa, including Nigeria, Liberia, and Senegal. The results of Nigeria’s research will play a crucial role in shaping the eventual effectiveness of these vaccines. She emphasized that the Institute of Human Virology is committed to ensuring that its studies adhere to the highest international standards so that findings not only address local concerns but also carry global significance. For her, the development of a safe and effective vaccine could be a game-changer, capable of dramatically reducing the annual toll of infections and deaths associated with Lassa fever.

She also acknowledged that while the centre has made significant progress in studying Lassa fever, research into other diseases such as HIV/AIDS has slowed in recent times due to the suspension of some foreign funding, particularly from the United States government. Despite these setbacks, she noted that the organisation continues to advocate for renewed financial support from both local and international partners, stressing that consistent funding is critical to maintaining momentum in the fight against viral diseases.

The importance of vaccine development cannot be overstated, especially in a region where healthcare resources are often stretched thin. Beyond the human suffering caused by Lassa fever, outbreaks disrupt local economies, overwhelm hospitals, and create widespread fear within communities. The disease tends to resurface during the dry season, when human contact with rodents increases, and without an effective vaccine, prevention largely depends on public health campaigns focused on hygiene and rodent control. However, these efforts have proven difficult to sustain across all affected areas.

The optimism around a single vaccine brings renewed hope not only to scientists and healthcare workers but also to the many families that have been devastated by the disease. The potential for one vaccine to protect multiple populations across different countries would simplify distribution, lower costs, and increase accessibility. This would mark a turning point in West Africa’s fight against one of its most persistent viral threats.

As Nigeria prepares to continue discussions at the upcoming symposium themed “Combating Viral Threats through Public Health Response and Research,” the findings on Lassa virus strains highlight how science can unlock solutions to long-standing challenges. While there are still hurdles to cross before a vaccine becomes available, the path forward looks clearer than ever before. For a country that continues to lose lives each year to Lassa fever, the possibility of a single effective vaccine represents more than a medical breakthrough it represents hope for stability, health security, and a future where one of the region’s deadliest diseases could finally be controlled.