EpiVax, Inc. (“EpiVax“) announces the publication “Evaluation of a Human T Cell-Targeted Multi-Epitope Vaccine for Q Fever in Animal Models of Coxiella burnetii Immunity” in Frontiers in Immunology, a collaboration with Massachusetts General Hospital’s (“MGH”) Vaccine and Immunotherapy Center, the Oxford Vaccine Group, Colorado State University, and Innatoss Laboratories B.V. The work was supported by the US Defense Threat Reduction Agency (DTRA), under contract HDTRA1-15-C-0020, for which MGH was the prime contractor.
Q Fever is a zoonotic disease caused by Coxiella burnetii bacterial infection. In addition to acute cases, a small but significant number of patients will develop a chronic infection with serious health risks such as endocarditis. This study is an important proof of concept for a new type of vaccine that has the potential to reduce hospitalization and severe outcomes.
Importantly, this study documents vaccine-immunogenicity in mouse and macaque models. The broad immune response to the vaccine candidate in the macaque model is an exciting finding that study authors hope to replicate in human trials.
The study also challenges the status quo of pursuing sterilizing immunity as an efficacy end-point for vaccine-challenge studies-particularly for a T cell-driven vaccine. Researchers focused on a robust, disease-limiting cellular (T cell) immune response to induce infection-clearing protection, markedly different from the traditional vaccine development goal of provoking an infection-blocking humoral (antibody) response.
On the potential for this new candidate, Ann Sluder, Associate Director of the Vaccine and Immunotherapy Center at MGH and lead author, said “The one existing Q fever vaccine, composed of inactivated bacteria, can cause severe reactions in some individuals and is approved for use only in Australia. The novel T cell-targeted vaccine is designed to stimulate disease-preventing immunity in humans while also avoiding the acute reactions that have prevented wider approval of the inactivated vaccine.”
Researchers aim to work closely with regulatory agencies to develop a preclinical testing plan suitable for a T cell-driven vaccine candidate. Advancing to human trials would be an important milestone for T cell vaccine technology.