An Improved PCV-2 Vaccine

Current PCV2 vaccines stimulate protective immunity to PCV2a and 2b serotypes but reducedprotection against evolving and emerging strains such as PCV2d 2g and 2h. We propose to useImmune Refocusing Technology (IRT) to reduce the immunogenicity of epitopes that stimulatesubtype-restricted immunity and refocus towards more broadly protective epitopes. Our first- generation IRT candidate demonstrated improved protection against PCV2d compared to acommercially available vaccine. We have designed two second-generation candidates to increasethe breadth of protection towards additional subtypes. The vaccine candidates are based on anattenuated strain which will reduce the cost of the vaccines and include a marker epitope fordistinguishing between immunized and infected swine. The project will be led by long-timecollaborators at Biological Mimetics Inc. and NDSU. BMI will design the IRT candidates andperform serological analyses of swine sera including cross-neutralization of PCV2d 2g and 2hviruses. Dr. Ramamoorthy at NDSU will produce the recombinant viruses and the challengestocks. Dr. Pillai at SDSU will perform the swine immunization and challenge experiment andanalyze tissues by pathology and histopathology. We aim to identify an improved PCV2 vaccinethat stimulates broadened cross-subtype protection that can be further developed in a Phase IIproject.