Development of efficacious replicon particle vaccines for swine influenza virus

Abstract

The alphavirus replicon technology has been utilized for many years to develop vaccines for both veterinary and human applications. Many developments have been made to the replicon platform recently resulting in improved safety and efficacy of replicon particle vaccines. This review provides a broad overview of the replicon technology and safety features of the system and reviews the current literature of replicon particle and replicon-based vaccines. Introduction Traditionally, veterinary vaccines have consisted of either modified live or inactivated preparations. Modified live vaccines (MLV) have the possibility of reverting to virulence with subsequent spread among surrounding animals. 9,45 Inactivated vaccines often generate insufficient cell-mediated immunity required for protection so must be combined with adjuvants that are able to induce the required immune response. 46,47 Thus, there has been a focus on “second-generation” vaccines, some of which have already been licensed for commercial veterinary use. 46 Alphavirus replicon-based vaccines represent a viable option for next-generation vaccine development. To date, alphavirus replicon-based vaccines have not been approved by any government regulatory agency for use in animals or humans. Alphavirus replicon particles (RP) are single-cycle, propagation-defective particles that