"The vaccine is designed to protect against two viruses of global health importance and could reduce the need for separate vaccination efforts." — Justin Ortiz, Study Principal Investigator
A New Dual Vaccine Targets Lassa Fever and Rabies
Researchers at the University of Maryland School of Medicine's Center for Vaccine Development and Global Health have reported promising results from an early clinical trial of LASSARAB, a novel dual vaccine designed to protect against both Lassa fever and rabies. The study, published in Nature Medicine, found the vaccine to be safe and effective at inducing immune responses against both viruses.
Trial Design and Results
The study involved 54 healthy adult volunteers from the Baltimore area. Participants were randomly assigned to receive either different doses of LASSARAB combined with an adjuvant, or a licensed rabies vaccine as a control.
- Two doses were administered 28 days apart.
- An interim analysis examined immune responses through 61 days post-vaccination.
- No serious adverse events were reported.
The candidate vaccine induced rapid and robust antibody responses against both Lassa and rabies viruses. In contrast, the control group only developed an immune response against rabies.
Ongoing Research
The study is still active. Researchers will continue to monitor safety and immune responses through 394 days post-vaccination to gather long-term data.
Why This Matters: The Threat of Lassa Fever
Lassa virus is identified by the World Health Organization as a significant public health threat in western Africa.
- 300,000 infections occur each year, resulting in 5,000 deaths (though actual numbers may be higher).
- The disease is particularly dangerous in pregnancy, with over 80% of late-term infections resulting in the death of the mother or fetus.
- There are currently no licensed vaccines for Lassa fever.
A Converging Crisis: Rabies and Climate Change
Regions where Lassa fever is common also face a high burden of rabies, a disease that is almost always fatal once symptoms develop. A single vaccine targeting both threats offers a pragmatic solution for vulnerable populations.
Furthermore, climate change is projected to expand the ecological range of the Lassa virus. By 2070, an estimated 700 million people worldwide could be at risk.
Expert Perspectives
- Stefan Kappe, CVD Director: Stated that the study highlights the center's commitment to tackling diseases of global significance.
- Mark T. Gladwin, UMSOM Dean: Emphasized that a vaccine is urgently needed as climate change extends Lassa fever's reach.
Vaccine Innovation and Storage
LASSARAB was developed by a research team at Thomas Jefferson University led by Matthias Schnell.
A key advantage of the vaccine is that it can be freeze-dried for storage, enabling distribution to areas with limited cold chain capacity.
The trial was funded by the National Institute of Allergy and Infectious Diseases.