Lassa virus (LASV) is the most dangerous viral pathogen in Africa in terms of annual number of human infections and fatalities resulting in an estimated 500,000 infections and 5,000 deaths per year.

LASV causes an acute viral hemorrhagic illness and is transmitted to people by contact with food or household items contaminated by rodents. Person-to-person infections and laboratory transmission can also occur, particularly in hospitals lacking adequate controls. Development of preventive measures for LASV is the priority for the World Health Organization (WHO) and the National Institutes of Health (NIH).

Expert Review of Vaccines, a peer-reviewed international medical journal published a review article on experimental LASV vaccines (Expert Rev Vaccines 2016; 15:1135-50). The review is authored by the University of Louisville and Medigen scientists. The lead vaccine candidates, reassortant ML29 and recombinant VSV/LASV, have been successfully tested in non-human primates and recommended by the international vaccine experts for clinical development. Both platforms have demonstrated safety, immunogenicity, and protective efficacy. ML29 vaccine also protected against distantly related LASV genotypes and therefore can be used for vaccination against multiple LASV strains in Africa.