Manufacturers: IDT Biologika
LASSARAB is an investigational adjuvanted inactivated rabies virus-vectored Lassa fever vaccine developed by Thomas Jefferson University and the University of Maryland. It is designed to provide dual protection against Lassa virus and rabies virus in a single formulation. In a first-in-human Phase 1 dose-escalation trial (NCT06546709) enrolling 54 healthy adults, two intramuscular doses administered 28 days apart demonstrated 100% seroconversion against both Lassa virus and rabies virus by day 61, with all recipients achieving rabies-neutralizing antibody titers exceeding the WHO correlate of protection (≥0.5 IU/ml). The vaccine was well tolerated with no serious adverse events. Results were published in Nature Medicine. LASSARAB is the only non-replicating Lassa vaccine candidate in clinical development and can be produced under BSL-2 conditions with lyophilization for thermostable storage.
LASSARAB is an investigational adjuvanted inactivated rabies virus-vectored Lassa fever vaccine developed by Thomas Jefferson University and the University of Maryland. It is designed to provide dual protection against Lassa virus and rabies virus in a single formulation. In a first-in-human Phase 1 dose-escalation trial (NCT06546709) enrolling 54 healthy adults, two intramuscular doses administered 28 days apart demonstrated 100% seroconversion against both Lassa virus and rabies virus by day 61, with all recipients achieving rabies-neutralizing antibody titers exceeding the WHO correlate of protection (≥0.5 IU/ml). The vaccine was well tolerated with no serious adverse events. Results were published in Nature Medicine. LASSARAB is the only non-replicating Lassa vaccine candidate in clinical development and can be produced under BSL-2 conditions with lyophilization for thermostable storage.
LASSARAB uses a chemically inactivated rabies virus vector to deliver the Lassa virus glycoprotein complex (GPC) as an immunogen. Following intramuscular administration, the vaccine induces robust humoral immune responses against both LASV-GPC and RABV glycoprotein. Protection against Lassa virus is mediated primarily through non-neutralizing antibodies with Fcγ receptor-mediated effector functions, including antibody-dependent cellular cytotoxicity (ADCC), rather than through neutralizing antibodies. This mechanism is consistent with observations from human Lassa survivors and preclinical nonhuman primate challenge studies, where vaccinated animals survived lethal LASV challenge despite the absence of pre-challenge neutralizing antibodies. Simultaneously, the vaccine elicits rabies-neutralizing antibody titers exceeding the WHO correlate of protection (≥0.5 IU/ml). The aPHAD-SE adjuvant (a synthetic TLR-4 agonist analog in a squalene oil-in-water nanoemulsion) enhances the magnitude and durability of the immune response.
LASSARAB is an investigational bivalent vaccine intended for dual protection against Lassa fever (caused by Lassa virus) and rabies (caused by rabies virus). It is being developed for use in regions where both diseases are endemic, particularly West Africa. As of the Phase 1 interim analysis, the vaccine is not yet licensed for any indication.
2 associated conditions
