Lassa Fever Vaccine Confers Full-Protection With 1-Dose

A Georgia-based biotechnology company announced the publication of an article entitled “A Single Dose of Modified Vaccinia Ankara Expressing Lassa Virus-like Particles Protects Mice from Lethal Intra-cerebral Virus Challenge.” 

The paper published in Pathogens on September 4, 2019, shows that a single intramuscular (IM) dose of GEO-LM01 provided 100 percent protection in mice challenged with a lethal dose of ML29 (a Mopeia/Lassa reassortant virus) delivered directly into the brain. 

According to GeoVax Labs, this is the 1st report showing that a single dose of a replication-deficient Modified Vaccinia Ankara (MVA) vector can confer full protection against a lethal challenge.

This is important news since Lassa fever cases surpass Ebola, Marburg, and all other hemorrhagic fevers except Dengue in public health impact.

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, causing up to 10,000 deaths, says the World Health Organization (WHO).

The WHO continues to advise all countries in the 'Lassa Fever Belt' of central West Africa on the need to enhance early detection and treatment of cases to reduce the case fatality rate as well as strengthen cross-border collaboration. 

The GEO-LM01 Lassa fever vaccine candidate is based on GeoVax’s novel Modified Vaccinia Ankara Virus-Like Particle (VLP) platform, which generates noninfectious VLPs in the individual being vaccinated. 

VLPs mimic a natural infection, triggering the body to produce a robust and durable immune response with both antibodies and T cells. 

GEO-LM01 is one component of a multivalent hemorrhagic fever virus vaccine being developed by GeoVax. The other vaccine components are for protection against Sudan virus (SUDV), Marburg virus (MARV), and Ebola virus (EBOV).

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 the Ebola virus.

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.

Nosocomial infections refer to any systemic or localized conditions that result from the reaction by an infectious agent or toxin, says the WHO.

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.