A recent study published in Nature Medicine on August 28, 2024, has revealed that the widespread deployment of a safe Lassa vaccine across 15 countries in West Africa could potentially save nearly 3,300 lives over a span of 10 years and prevent up to $128 million in societal costs.
The research, conducted by the Universities of Oxford and Liverpool, as well as the Liverpool School of Tropical Medicine, emphasized the importance of vaccinating against Lassa Fever to prevent illness, high treatment costs, and potential poverty.
The study, led by David Smith from the University of Oxford, highlighted the necessity of an effective vaccine that could target both infection and disease.
Additionally, the research team explored the impact of introducing a vaccine for a hypothetical Lassa-like virus with pandemic potential known as Lassa X, within a short timeframe to prevent outbreaks from escalating.
The findings underscored the significance of global initiatives such as the “100 Days Mission” by CEPI, aiming to deliver vaccines against potential disease outbreaks swiftly to prevent them from turning into pandemics.
The World Health Organisation has pointed out Lassa fever as a significant threat for future outbreaks, especially considering the risks posed by climate change and other factors.
Symptoms of Lassa fever include fever, headache, muscle pain, and vomiting, with severe cases resulting in facial swelling and bleeding.
The study estimated an average of 23,700 hospitalizations and 3,900 deaths per year due to Lassa fever in West Africa, though the actual impact could be higher due to limited access to healthcare.
The research suggested that a proactive, population-wide vaccination strategy would be more effective in reducing the burden of Lassa fever compared to reactive response to local outbreaks.
Smith said, “To our knowledge, this is the first study to estimate the burden of disease for Lassa fever and to project the impacts of Lassa vaccination campaigns on population health and economies. One major potential benefit of current investment in Lassa vaccine development is increased readiness to rapidly develop and deploy vaccines against future Lassa variants with pandemic potential.”
The researchers concluded, “Our analysis suggests that vaccination campaigns targeting known Lassa fever hotspots will help to alleviate the large health-economic burden caused by this disease. However, expanding vaccination beyond WHO-classified ‘endemic’ districts will be necessary to prevent the large burden of disease estimated to occur in neighbouring areas not currently classified as endemic.”
Enhanced surveillance is crucial to gain a deeper understanding of Lassa fever’s spread and impact in West Africa, enabling the development of targeted vaccination strategies that effectively reach high-risk individuals and maximize public health benefits.
Richard Hatchett, Chief Executive Officer of the Coalition for Epidemic Preparedness Innovations (CEPI), noted, “Lassa fever is a serious public health problem in West Africa and is already threatening to spread to other regions as climate and environmental change increase epidemic risk.”
The World Health Organization reaffirms its dedication to collaborating with member states, CEPI, and all partners to accelerate the development of a Lassa fever vaccine and essential tools to combat the disease and safeguard communities, with Hatchett stressing, “The time for action is now.”
Additionally, Dr. Virgil Lokossou, Head of the Preparedness and Response Division at the West African Health Organization, noted,
“Lassa fever continues to pose a serious public health threat in West Africa, severely impacting lives, health, and economic systems. This modelling study highlights the burden of Lassa fever and its significant socioeconomic consequences, underscoring the urgent need to accelerate vaccine research and development as part of regional preparedness and response efforts.”
Joanne Turner, Research Associate at the University of Liverpool and joint first author, highlighted, “The Lassa vaccination campaigns included in our analysis were designed to reflect realistic assumptions about vaccine stockpile and administration. Consequently, the impacts of our simulated Lassa vaccination campaigns were modest in countries other than Nigeria, Guinea, Liberia, and Sierra Leone. Yet, the data underlying our model suggest that there is likely already a significant burden of Lassa fever outside these countries.”
Professor Déirdre Hollingsworth of the University of Oxford’s Big Data Institute stated, “Lassa fever predominantly affects low-income populations in rural areas and is likely to be highly underreported due to poor healthcare access in these areas. This analysis highlights the potential impact of a vaccine on these populations.”
