Development of an Empty Viral Capsid Vaccine against Foot and Mouth Disease

Foot-and-mouth disease (FMD), a highly infectious viral disease of cloven-hoofed animals, is economically the most important disease of domestic animals. Although inactivated FMD vaccines have been succesfully used as part of comprehensive eradication programs in Western Europe, there are a number of concerns about their safety. In this proposal, we have attempted to develop a new generation of FMD vaccines that addresses these concerns. Specifically we have cloned the region of the viral genome coding for the structural proteins and the proteinase responsible for processing of the structural protein precursor into both a DNA vector and a replication-deficient human adenovirus. We have demonstrated the induction of an FMDV-specific immune response and a neutralizing antibody response with the DNA vectors in mice, but preliminary potency and efficacy studies in swine are variable. However, the adenovirus vector induces a significant and long-lived neutralizing antibody response in mice and most importantly a neutralizing and protective response in swine. These results suggest that the empty capsid approach is a potential alternative to the current vaccination strategy.