16 Feb CMV Virus Based Vaccine Protects Non-Human Primates From Ebola

MedicalResearch.com Interview with:

Dr. Michael Jarvis

Dr. Michael A. Jarvis, PhD
Reader in Virology & Immunology
Director of Graduate Studies,
School of Biomedicine & Healthcare Science,
University of Plymouth 

Medical Research: What is the background for this study?
Dr. Jarvis: This study is the latest in a series from a collaborative team involving scientists from the National Institutes of Health, University of California, Riverside and Plymouth University in the UK, and is an example of how I think science works best – when individuals with complementing areas of expertise come together to address a problem.

Medical Research: What are the main findings?

Dr. Jarvis: A main finding of the study is that the protection against Ebola virus that we observed in earlier studies in the mouse model translates to the experimental non-human primate model. This is a critical step in development of a vaccine for use in humans and other apes. At the applied level, we are interested in further development of this vaccine in a number of directions.

• First, in a replication-defective format for use in humans (other studies suggest that replication-defective versions of CMV maintain ability to induce immune responses).
• Second, we are interested in developing CMV as a self-disseminating vaccine to protect inaccessible wild African ape populations against Ebola virus. Ebola has decimated wild apes and these animals also serve as a main source of transmission of the virus into the human population. This would be a win-win situation for both ape conservation and human health.An additional and unexpected finding was that expression of the Ebola virus target antigen (called glycoprotein, GP) corresponded to an anti-Ebola immune response heavily biased towards antibody production and away from T cells. This phenomenon, which we are in the process of examining further, has never been seen for any other primate herpesvirus-based vaccine. It was associated with expression of GP at later times in the replication cycle of the CMV vaccine. We are currently constructing additional versions of these vaccines that express their target proteins at different times to examine further the impact of time of antigen expression on antibody versus T cell bias. Clearly this ability to modulate the antibody: T cell bias of the adaptive immune response could have substantial importance for vaccination in general. This phenomenon is also mechanistically very interesting at a more basic scientific level.

In the absence of detectable T cells against Ebola glycoprotein, the data presents the depletion of antibodies following challenge gives a graphic visualization of the antibody mediated protection, with the only animal to succumb to Ebola virus being the one in which antibody levels dropped to below detectable levels.

Citation:

Andrea Marzi, Aisling A. Murphy, Friederike Feldmann, Christopher J. Parkins, Elaine Haddock, Patrick W. Hanley, Matthew J. Emery, Flora Engelmann, Ilhem Messaoudi, Heinz Feldmann, Michael A. Jarvis. Cytomegalovirus-based vaccine expressing Ebola virus glycoprotein protects nonhuman primates from Ebola virus infection.
Scientific Reports, 2016; 6: 21674 DOI: 10.1038/srep21674

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Dr. Michael Jarvis (2016). CMV-Virus Based Vaccine Protects Non Human Primates From Ebola 

Last Updated on February 16, 2016 by Marie Benz MD FAAD