Lassa Fever Vaccine Candidate To Report Significant Efficacy

A biotechnology company specializing in developing human vaccines announced in a press release an oral presentation entitled, 'A Single Dose of MVA-Based Lassa Virus Vaccine Provides Complete Protection in a Mouse Lethal Challenge Model', will be given during the Annual Meeting of the American Society for Virology, being held July 20, 2019. 

In her pending talk, Senior Scientist, Mugdha Vasireddi, Ph.D., will discuss the preclinical efficacy studies of GEO-LM01, a novel vaccine candidate for Lassa fever constructed on a Modified Vaccinia Ankara (MVA) vector expressing 2 immunogens derived from the Lassa virus. 

The highlight of this small, non-human study, is this is the first report that a replication-deficient MVA vector can confer full protection against Lassa after a single vaccine dose. 

This research is important because there is no treatment or vaccine available to stem Lassa fever epidemics. 

And, in contrast to the unpredictable epidemics of filoviruses such as Ebola, Lassa fever is endemic in West Africa, with an annual disease incidence of over 300,000, leading to 5,000 to 10,000 deaths, says the World Health Organization (WHO). 

Upon vaccination, these immunogens form Virus-Like Particles (VLPs) in the host which will, in turn, induce immunity against subsequent infections with the Lassa virus. 

Immunogenicity and efficacy of the GEO-LM01 vaccine were tested in a mouse challenge model. 

A single intramuscular dose of GEO-LM01 protected 100% of normal mice challenged with a lethal dose of ML29, a Mopeia/Lassa reassortant virus, delivered directly into the brain.   

In contrast, all control animals died within one week.   

The vaccine-induced low levels of antibodies but strong CD4+ and CD8+ T cell responses. 

The data being presented by Dr. Vasireddi contributed to the body of information resulting in a $300,000 Fast Track Phase I/II Small Business Innovative Research (SBIR) grant to GeoVax from the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH) in April 2018. 

As well as a $2.4 million grant awarded to GeoVax in September 2018 by the U.S. Department of Defense, in support of advanced preclinical testing of the GeoVax Lassa fever vaccine.

Lassa Fever symptoms & transmission

Lassa fever is caused by an infection with Lassa virus, a member of the Arenaviridae virus family. The virus can cause severe hemorrhagic illnesses with up to 50 percent case fatality rates in an overlapping region with Ebola virus, says the WHO.

The Lassa virus is transmitted to humans by African rats that live in large numbers in agricultural areas near human habitations. The virus can also be transmitted from human to human through nosocomial infections.

Lassa Fever news

• Lassa Fever Vaccine Candidate Passes Animal Test
• Tropical Disease Priority List Expanded by FDA

GeoVax Labs, Inc. is a clinical-stage biotechnology company developing human vaccines against infectious diseases and cancer using a novel patented Modified Vaccinia Ankara-Virus Like Particle (MVA-VLP) based vaccine platform.