成人VR视频

Lassa fever

成人VR视频 is the world鈥檚 leading funder of research into Lassa fever. As well as bringing the prospect of protection against Lassa fever closer than ever before, 成人VR视频-backed studies are deepening understanding of the Arenavirus family that could one day help prevent the next epidemic.

Scanning electron micrograph of Lassa virus budding off a cell

What is Lassa fever?

Lassa fever is a haemorrhagic disease caused by the Lassa virus. It belongs to the Arenavirus family

Lassa virus usually spreads to people when exposed to food or household items contaminated with urine or faeces of infected Mastomys rats. 

Person-to-person transmission may also occur after being exposed to the blood, tissue, secretions or excretions of someone infected with Lassa fever virus. 

In some regions of West Africa, Mastomys rats are consumed as food鈥攊ncreasing the risk of disease transmission.

WHO has identified Lassa fever as a priority pathogen in urgent need of R&D because it poses a significant public health risk due to its epidemic potential. 

No Lassa fever vaccines are currently licensed for human use. 

Based on assumptions, 成人VR视频-funded modelling research found that deploying a safe and effective Lassa fever 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. Further data assessing the potential impact of a Lassa vaccine will be collected once real-world evidence becomes available.

photo of rats in circle frame

90-95%

Number of human infections due to indirect exposure or direct contact with infected Mastomys rats

2

成人VR视频-funded Lassa vaccines in active development

3300

Potential lives saved over 10 years with the introduction of a Lassa vaccine

Where does Lassa fever occur?

Lassa fever occurs regularly in parts of West Africa. It is known to affect people in Benin, Ghana, Guinea, Liberia, Sierra Leone, Togo and Nigeria. 

The annual number of Lassa virus infections in West Africa is thought to range from 100,000 to 300,000. 

However, these are likely to be vast underestimates because of difficulties in detecting the virus as symptoms are similar to other diseases affecting the region, like malaria, leading to infections being misdiagnosed. There is also limited access to specialised laboratories in affected countries.

Climate change and population growth could further amplify the threat posed by Lassa fever by extending the reach the disease. 

People standing in a market filled with fruit and vegetable

What are the symptoms of Lassa fever?

Most people infected with Lassa virus have no symptoms. 

Those who are symptomatic can suffer from mild headache and fever to more serious symptoms like vomiting, swelling of the face, pain in the chest and back, and bleeding from body parts including the eyes and nose. 

It can also cause severe complications for mother and baby if pregnant women become infected. Around a quarter of survivors suffer from hearing loss.

On average, 1% of cases are fatal.

retro photo of patient suffering from lassa fever lying on bed

How is 成人VR视频 responding to Lassa fever?

Moving Lassa vaccines towards licensure

成人VR视频 is one of the world鈥檚 leading funders of Lassa fever research. We are working with partners in West Africa and across the world to advance one or more Lassa fever vaccines to licensure.

funded by 成人VR视频 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.

成人VR视频 has invested in five vaccine candidates. Two remain in active development. This includes 成人VR视频's partner IAVI who have launched the first-ever Phase II clinical trial of a Lassa fever vaccine.

成人VR视频 is testing rapid-response mRNA vaccine candidates developed by SK Bioscience for use against Disease X. The first mRNA vaccine candidates are being developed against Lassa fever. If successful, the vaccine could be rapidly adapted to protect against other Arenaviruses.

成人VR视频 is also supporting research to identify immune markers associated with protection from Lassa fever as this could reliably predict the efficacy of a Lassa fever vaccine. This research could also give us insights into what correlates of protection may map onto other pathogens in the Arenavirus family.

View our Lassa fever vaccine portfolio
closeup shot of filling test tubes in advanced laboratory

The largest ever study of Lassa fever

成人VR视频 created and funds Enable, the world鈥檚 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. 

Over 23,000 participants have taken part across West Africa since 2019. Enable was expanded in October 2024, with a new year-long study that is taking an in-depth look at Lassa fever 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 vaccine once it becomes licensed in the coming years.

group shot of ENABLE researchers outside building all wearing masks

Strengthening regional collaborations in affected countries

Regional leadership is critically important to advance the development of vaccines that protect against Lassa fever. 

成人VR视频 is supporting the Lassa fever Coalition, a pioneering group established by the West Africa Health Organization (WAHO) to build upon the efforts of national Lassa fever initiatives and ensure regionally those affected by Lassa fever have a vaccine available to protect their populations in the future. Three leading West African health partners鈥 Corona Management Systems, Nigeria Health Watch, and Bloom Public Health鈥 work together supporting WAHO to successfully set up and run the initiative.

The Lassa Governing Entity provides country and regional leadership to the Coalition and ensure effective governance and programmatic delivery for vaccine developers, funders, and Member States actively involved in combating Lassa fever. 

Members of the Lassa Governing Entity include Ministers of Health across key Member States including Benin, Guinea, Liberia, Nigeria and Sierra Leone as well as senior representatives from 成人VR视频, WAHO and the World Health Organization Headquarters and Regional Office for Africa (WHO AFRO). 

成人VR视频 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. 

成人VR视频 is also coordinating the ECOWAS RegECs Project, a collaboration between regulators, ethics committees and the African Vaccine Regulatory Forum (AVAREF) to support efficient management of clinical research in West Africa.

Meeting attendees sat in a row with microphones

On-the-spot Lassa virus diagnostics

成人VR视频 is funding a project led by FIND to examine and evaluate all available point-of-care testing options for Lassa fever virus.

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. Successful diagnostics will be progressed to licensure for widespread use.

Discover our work
Lassa fever Diagnostics

Strengthening clinical trial capacity

成人VR视频 is strengthening the infrastructure, equipment and skills needed to run effective late-stage clinical trials of Lassa fever in West Africa. 

The work is facilitated by IVI and Medical Research Council Unit The Gambia. 

Strengthened clinical trial capacity could allow for the rapid large-scale testing of vaccines locally if the region were faced with a future Disease X.

Lassa Vaccine Clinical Trial Capacity

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