Thomas Jefferson University announces it has initiated a phase 1 clinical trial for a Lassa virus (LASV) vaccine developed at Jefferson in collaboration with the University of Maryland, Baltimore (UMB), at the Center of Vaccine Development and Global Health, UMB. Currently, there are no approved vaccines against the Lassa virus. The clinical study is a dose-ranging study that will assess the safety and immunogenicity of the candidate vaccine for both the rabies virus and LASV.

The experimental vaccine is based on an attenuated and killed rabies virus vaccine similar to current rabies vaccines and has an additional LASV protein. Rabies vaccines are safe for all people, including pregnant women and children, and have been administered to millions of people worldwide with few side effects.

Lassa virus causes a viral hemorrhagic disease that can be fatal and causes permanent hearing loss in 30% of survivors. Lassa virus is endemic in West Africa, and it has a reservoir in rodents. There are an estimated 100,000 to 300,000 human infections yearly, which cause about 5,000 deaths. In addition, person-to-person transmission of LASV has been described. Notably, on Oct. 28, 2024, a middle-aged resident of Iowa succumbed to the LASV-induced disease after returning from a trip to West Africa. This was the ninth case in the U.S. since 1969.

Source: Thomas Jefferson University