IAVI’s Lassa fever vaccine reveals promise in early scientific trials

West Africa is one step nearer to being protected towards the lethal Lassa fever illness with IAVI’s vaccine candidate exhibiting promise within the first stage of scientific testing.

CEPI-backed analysis, revealed in the present day within the New England Journal of Medicine, reveals that over 100 wholesome adults enrolled in a Phase I trial within the US and Liberia who obtained one dose of the Lassa fever vaccine candidate generated a strong and sustained immune response. Testing additionally discovered the vaccine candidate, generally known as rVSVΔG-LASV-GPC, has a suitable security profile.

rVSVΔG-LASV-GPC makes use of the identical vaccine expertise ‘backbone’ because the licensed Merck Ebolavirus vaccine, ERVEBO.

“These encouraging results add to a growing body of evidence that demonstrates the safety and immunogenicity of IAVI’s single-dose Lassa vaccine candidate” says Dr Swati Gupta, Vice President and Head of Emerging Infectious Diseases and Epidemiology at IAVI.

A Phase II trial, supported by CEPI, has now commenced throughout Nigeria, Sierra Leone and Ghana, making rVSVΔG-LASV-GPC essentially the most superior Lassa fever vaccine candidate in scientific testing. The newest analysis examine goals to generate further proof on the efficiency of the Lassa fever vaccine in a bigger set of volunteers. 

Lassa fever is widespread throughout West Africa, with annual outbreaks the place lots of of 1000’s of individuals are considered affected occurring from November via to May. The virus is primarily unfold by contaminated rodents generally known as Mastomys rats, though infections may go between folks, particularly in healthcare settings. 

While most individuals are considered asymptomatic, some folks can endure from extra extreme signs together with vomiting, swelling, chest ache and bleeding from a number of physique elements together with the eyes and nostril. Infection can show deadly in some circumstances and pregnant girls can endure from extreme problems for each mom and child. 

While a identified menace to West Africa, there may be concern that up to 600 million people could be at risk of Lassa fever by 2050 on the African content material due to the altering local weather and elevated motion of individuals.

CEPI is without doubt one of the world’s main funders of Lassa fever analysis. We are working with companions in West Africa and around the globe to organize for future outbreaks by advancing a number of Lassa fever vaccines to licensure. 

“The promising Phase 1 data for IAVI’s vaccine candidate takes us one step closer towards a much-needed Lassa fever vaccine which, if successful, could save thousands of lives and avert millions of dollars of societal costs in the West African countries that bear the burden of this disease” says Dr Kent Kester, Executive Director of Vaccine R&D at CEPI.

News of the optimistic vaccine findings follows the historic endorsement of a communiqué on the Lassa International Conference in September 2025, the place West African Ministers of Health reaffirmed their dedication to advance a Lassa fever vaccine to licensure. 

The communiqué recognises the necessity to get an inexpensive Lassa fever vaccine to the individuals who want it most throughout the area and highlights how the programme of labor, led by the Lassa fever Coalition, is a pioneering cross-country effort and serves as a cornerstone of pandemic preparedness for the area. Regional leaders dedicated to supporting the event of IAVI’s Lassa vaccine candidate via a collaborative co-funding strategy and joint motion to mobilize and safe sources via advocacy and regional coordination.