|Mason, Peter - UNIV OF TEXAS, GALVESTON|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: January 10, 2006
Publication Date: March 1, 2009
Citation: Mason, P.W., Grubman, M.J. 2009. VACCINES TO CONTROL FOOT-AND-MOUTH DISEASE. Book Chapter 22: 361-377. Interpretive Summary: In this chapter, we discuss the history of foot-and-mouth disease (FMD), an economically devastating disease of cloven-hoofed animals, and its economic impact on affected countries. We present a brief description of both the disease and the causative viral agent, FMD virus (FMDV). We then discuss in some detail the development of traditional vaccines for FMD and describe some of the limitations of this vaccine. As a result of these limitations researchers for the past 25-30 years have been attempting to develop alternative disease control approaches and we describe the various strategies as well as their shortcomings. We discuss in more detail the most successful current second generation FMD vaccine based on a genetically engineered viral subunit which does not contain infectious FMDV and lacks the genetic information for a number of viral nonstructural proteins. Thus, production of this vaccine does not require expensive high-containment manufacturing facilities, can be made in the U.S., which currently prohibits work with infectious FMDV on the mainland, and animals inoculated with this marker vaccine can readily be differentiated from infected animals using diagnostic assays empolying the viral nonstructural proteins not present in the vaccine. This vaccine is currently most effectively delivered by a replication-defective human adenovirus type 5 vector (Ad5). We also discuss a complementary approach to induce rapid protection prior to the onset of vaccine-induced immunity. The antiviral agent type 1 interferon can rapidly inhibit FMDV replication and we summarize studies that demonstrate that this reagent, also delivered by an Ad5 vector, can protect inoculated swine when challenged with virulent FMDV 1 day later. We finally summarize our prospects for the future by describing the different disease control approacthes required in disease-free countries and enzootic countries, but emphasize the need for developed countries to share resources and information with developing countries as the best way of controlling FMD worldwide.
Technical Abstract: Foot-and-mouth disease (FMD) is a devastating disease of livestock that has had a significant impact on world economies and public health. Its importance to mankind is confirmed by the fact that FMD virus (FMDV) was the first animal virus discovered, and that FMD was among the first animal diseases for which vaccines were developed. Due to its rapid spread and the high cost of eradication campaigns, countries that are free of the disease are susceptible to huge economic losses if the disease were to be introduced either accidentally or deliberately in an act of agroterrorism. Vaccines developed in the 1950s and 60s have helped to control this scourge in many nations, and these products have been further developed and refined over the last 30 years. Although these vaccines are very useful as part of eradication campaigns in countries where FMDV is enzootic, it is not feasible to use these products in prophylactic vaccination of entire regions. In addition, these vaccines are not ideally suited to control outbreaks in disease-free countries. Thus, for the portions of the world that are currently FMD-free, there is a need for new vaccines that can be applied in the areas surrounding an outbreak to rapidly dampen the spread of infection. Although the market for this type of vaccine is small, there are several groups trying to satisfy this important need. This chapter will detail the history of FMD vaccine development emphasizing recent advances and prospects for future development.