Challenges in Having Vaccines Available to Control Transboundary Diseases of Livestock

The global human population is growing at a rapid rate leading to the need for continued expansion of food animal production to meet the world's increasing nutritional requirements. As a consequence of this increased production demand, the use of high volume, animal dense systems have expanded providing high quality protein at reduced costs. Backyard animal production has also expanded. This increased food animal production has facilitated the rapid spread, mutation, and adaptation of pathogens to new hosts. This scenario continues to drive the emergence and reemergence of diseases in livestock species increasing the urgency for development and availability of vaccines for transboundary animal diseases (TADs). Even though vaccines are widely recognized as being an essential tool for control of TADs, there are many scientific, economic, political, and logistical challenges to having vaccine available to control an outbreak. This article will focus on examples of the challenges associated with having vaccines available for emergency response, as well as the characteristics of "ideal" TAD vaccines, the need for complementary diagnostic assays, and hurdles involved in bringing efficacious veterinary TAD vaccines to market including regulatory constraints and considerations for stockpiling vaccines for emergency use in non-endemic countries. Examples will also highlight the complicated interplay between animal health and human health and demonstrate the lasting benefits that can be gained from an efficacious vaccine.