In their search for new and more effective vaccines, OHSU scientists are still unraveling the intricacies of those operations of the immune system that protect us from microbial infection. By understanding the mechanisms involved with improving T cell and B cell responses to foreign antigens, we will be able to develop more effective vaccines against viruses and other microbial pathogens.

Mark Slifka, Ph.D. and his colleagues are investigating the underlying mechanisms of humoral and cell-mediated immunity against acute and chronic viral infections. This work has included developing several models of viral infection and/or vaccination in order to address basic immunological questions related to the development and maintenance of long-term protective immunity.  This is collectively referred to as “immunological memory”. Dr. Slifka’s group has also developed a series of clinical studies in which they analyze immunological memory directly in human subjects. During the course of this work, they study a number of viruses including arenaviruses (lymphocytic choriomeningitis virus, LCMV), alphaviruses (chikungunya virus, Eastern-, Western-, and Venezualen equine encephalitis viruses), orthopoxviruses (vaccinia, cowpox, monkeypox, smallpox) and flaviviruses (West Nile virus, yellow fever, dengue and zika).

The combination of basic research in animal models and applied research in clinical studies involving both healthy and immunocompromised populations has provided the opportunity to better define the requirements for immunological memory and to learn how to develop more effective diagnostics and vaccine candidates.

These experiments lay the foundation for future studies in which Slifka and his team plan to develop new vaccines and determine the mechanisms involved with building strong vaccine-induced immunity. They have discovered a new hydrogen peroxide (H₂O₂)-based approach to vaccine development that results in safer, more effective human and animal vaccines. Dr. Slifka and his colleagues recently launched a first-in-man H₂O₂-based West Nile virus vaccine clinical trial.  Details of the Phase I clinical trial describing HydroVax-001 West Nile virus can be found at ClinicalTrials.gov (ClinicalTrials.gov Identifier: NCT02337868).