Press release
Monday March 17, 2025
Lassa fever is a viral hemorrhagic disease that can be fatal and causes permanent hearing loss.
A sponet clinical trial of the National Institutes of Health (NIH) of a candidate vaccine to prevent Lassa fever began to register participants in the Maryland University School of Baltimore. Lassa fever is a viral hemorrhagic disease which can be fatal and which causes permanent hearing loss to a third of those who contract it. The Lassa virus spreads by rodents, called multimammatic rats, which are from many countries in West Africa. The virus can also be distributed from person to person. Currently, there are no drug treatments or specific vaccines for Lassa fever. The National Institute of Infectious Allergies and Diseases of NIH (NIAID) sponsors the phase 1 trial.
“The candidate vaccine tested in this trial was developed by a research team supported by NIH at Thomas Jefferson University in Philadelphia,” said Niaid director Jeanne Marzzo, MD, MPH “The progress of this laboratory candidate on a first clinical trial is a promising step towards vaccination to prevent Lassa”.
The trial will register up to 55 healthy adults aged 18 to 50 to test the safety and immunogenicity of three different concentrations of the vaccination candidate. Participants will receive two injections, delivered to 28 days apart, either from the vaccine candidate, or a vaccine against rabies under food and drug license (control).
In Research published in 2024Matthias Schnell, Ph.D., and colleagues from the University of Thomas Jefferson tested the experimental vaccine, known as Lassarab, in non -human primates. They found that two doses of the vaccine, delivered 28 days apart, protected all immune animals that were exposed to large and lethal quantities of Lassa virus six weeks after the second inoculation.
Lassarab is based on a weakened rage vaccine (attenuated) which is subsequently inactivated to make the candidate for the vaccine. The experimental vaccine is then modified so that it expresses all the proteins of the rabies found in the vaccine against inactivated rabies with an surface protein of the lassa virus called a glycoprotein precursor (GPC). If Lassarab turns out to be sure and causes a good immune response both to rabies and lassa GPC proteins, it could be used to prevent the two diseases while waiting for other tests in clinical trials and subsequent approval by the FDA.
Additional information on the new clinical trial is available to Clinicaltrials.gov Using the identifier NCT06546709.
Niaid conducts and supports research – in NIH, the United States and the world – to study the causes of infectious and immune mediation, and to develop better means of prevention, diagnosis and treatment of these diseases. Press releases, information sheets and other Niaid materials are available on the Niaid website.
On the National Institutes of Health (NIH):The NIH, the country’s medical research agency, includes 27 institutes and centers and is a component of the American department of health and social services. NIH is the main federal agency that leads and supports basic, clinical and translational medical research, and studies the causes, treatments and remedies for common and rare diseases. For more information on NIH and its programs, visit www.nih.gov.
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