Researchers have developed a vaccine against Lassa virus (LASV) using an inactivated rabies virus-based vaccine that includes a LASV protein. The LASSARAB vaccine was effective in nonhuman primates given a two-dose regimen, and is a good candidate for clinical trials, according to authors of a new study published in npj Vaccines.
The rabies virus platform is well-suited to the hot African climate where LASV is endemic.
“Rabies virus (RABV) is a promising vaccine platform that has advantages over the (other) vaccine platforms…RABV has been successfully used as a vaccine platform for various pathogens, including LASV28 and a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine, CORAVAX, that has been tested in a phase I human clinical trial. The rabies vaccine is administered as an inactivated vaccine, has a well-established safety profile, and provides long-term protective immune responses to the rabies antigens.”
Currently, there are no FDA-licensed vaccines or specific therapeutics for Lassa fever. LASV, spread by rodents, infects an estimated 300,000 to 500,000 people annually, with an overall case fatality rate of between 1 and 2%. For patients needing hospital care, however, the fatality rate increases significantly – as high as 69% in one study from Sierra Leone.
The areas where LASV is endemic are also endemic to RABV, and LASSARAB can provide protection against both viruses. The WHO estimates that 95 percent of the estimated 59,000 human rabies deaths per year occur in Africa and Asia. Nearly all human rabies deaths are caused by bites or scratches from infected dogs. Effective rabies vaccines and post-exposure shots are available, but many deaths still occur in resource-limited countries.
Scientists at Thomas Jefferson University and the United States Army Medical Research Institute of Infectious Diseases led the work. The National Institutes of Allergy and Infectious Diseases (NIAID) provided funding for the research.
READ MORE:
Inactivated rabies-based Lassa fever virus vaccine candidate LASSARAB protects nonhuman primates from lethal disease. NPJ Vaccines, 9 August 2024.
Tetravalent rabies-vectored filovirus and Lassa fever vaccine induces long-term immunity in nonhuman primates. The Journal of Infectious Diseases, 9 January 2021.
Non-neutralizing antibodies elicited by recombinant Lassa–Rabies vaccine are critical for protection against Lassa fever. Nature Communications, 11 October 2018.
Sources: National Institutes of Allergy and Infectious Diseases, NPJ Vaccines, Nature Communications, World Health Organization