Control of Foot-and-Mouth Disease When Vaccines are Not Available

Abstract

Vaccination and depopulation are the methods for control of Foot-and-Mouth Disease (FMD). Another tool is needed to manage FMD Virus (FMDV) if sero-type vaccines are unavailable. The USDA plans to vaccinate cattle if there is a major FMDV outbreak in the USA, but this plan is hampered by the lack of a stockpile of FMDV vaccines to treat millions of animals in a timely fashion. In the absence of FMDV specific vaccines strategies to induce or administer interferon (IFN) might limit FMDV replication and disease in cattle and swine. A group of USDA Animal Research Service (ARS) scientists have reported that the FMDV establishes infection in susceptible cells/hosts by its ability to subvert key host defenses, specifically the inducible IFN response. FMDV inhibits production of IFN alpha (α) [l] and blocks a key IFNinducible, antiviral pathway, i.e.Double-Stranded RNA (dsRNA) dependent Protein Kinase R (PKR) [2]. Moreover, FMD Virion Protein 1 (VP1) has been specifically identified as a viral-origin IFN suppressor molecule by interacting with soluble resistancerelated calcium protein sorcin [3]. Since a key FMDV control method by host cells is suppression of IFNα production by FMDV-infected cells then exogenous treatment with IFNα or induction of endogenous IFN should help control FMD. Indeed, this vulnerability of FMDV to IFN has led to a novel viral disease control strategy using recombinant replication-defective human adenovirus 5 vector containing various species IFN genes. Results varied by species.