High Profile Diseases - Ebola Virus

Robert Lanford (SNPRC)

The Ebola virus kills up to 70% of the people it infects, making it one of the most virulent viruses that infects humans. Scientists around the world are pursuing a preventive vaccine and drug treatments for the Ebola virus, and research with nonhuman primates is providing a powerful means in this pursuit because of the animals’ physiological and immunological similarities to humans. This similarity is key in determining if newly developed vaccines and therapies can provide life-saving and enhancing solutions for humans.

The disease course and pathogenesis of Ebola virus in rhesus and cynomolgus macaques and marmosets is very similar to that of humans. Major characteristics of this disease in nonhuman primates and humans are profound lymphopenia, disseminated intravascular coagulation and hemorrhagic and septic shock. Only nonhuman primate models fully recapitulate these key features of disease. Macaques provide highly relevant opportunities to more fully define mechanisms of pathogenesis and, importantly, to test and develop both vaccines and drug therapies against filoviruses. Several vaccines that express Ebola virus antigens in genetically engineered virus vectors have shown efficacy against experimental challenge of immunized macaques with Ebola virus. Encouragingly, human testing of an experimental Ebola vaccine developed by the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID) and the National Institutes of Health will begin soon. Scientists in the Department of Virology and Immunology at Texas Biomedical Research Institute (host institute to the Southwest National Primate Research Center) are testing multiple vaccines and antivirals for Ebola in nonhuman primates that are also showing promising results.

Also, USAMRIID and the National Microbiology Laboratory of the Public Health Agency of Canada in Winnipeg used rhesus macaques to develop an experimental triple monoclonal antibody called ZMapp¹ that some patients have received. ZMapp is now being produced in tobacco plants by Mapp Biopharmaceuticals, a small biotech company in San Diego. The drug was previously tested in rhesus monkeys at the USAMRIID with promising results. ZMapp is not yet approved for human use.

¹Qiu X et al, Reversion of advanced Ebola virus disease in nonhuman primates with ZMapp. Nature. 2014.