Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/1/2005
Publication Date: 5/23/2005
Citation: Pacheco, J.M., Brum, M.C., Moraes, M.P., Golde, W.T., Grubman, M.J. 2005. Rapid Protection of Cattle from Direct Challenge with Foot-and-Mouth Disease Virus (FMDV) by Inoculation with an Adenovirus Vectored FMDV Subunit Vaccine. European Study Group on the Molecular Biology of Picornaviruses (ERUOPIC) 2005. P. I22. Interpretive Summary:
Technical Abstract: Foot-and-mouth disease virus (FMDV) is a highly contagious pathogen of cloven-hoofed animals including cattle and swine. Recent outbreaks in a number of previously disease-free countries have had significant adverse economic effects. The use of the current FMD vaccine, an inactivated whole virus preparation, has a number of drawbacks including the inability to reliably differentiate vaccinated from infected animals using currently approved diagnostic assays and the requirement of expensive high-containment facilities for vaccine production. To address these concerns we have constructed an FMDV subunit vaccine containing only the capsid and 3C proteinase coding regions of the viral genome. The absence of the coding region of a number of viral nonstructural proteins, in this vaccine, allows the use of currently approved companion diagnostic assays to unequivocally distinguish vaccinated from infected animals. We have previously demonstrated that swine inoculated with one dose of this subunit vaccine, delivered in a replication-defective human adenovirus type 5 (Ad5) vector, were protected when challenged 7 days later with homologous virus. In the current study, we have attempted to extend these results to cattle, the most economically important animals susceptible to FMD. Five cattle were given a single inoculation of 5 x 10 to the 9th power pfu of the Ad5-FMDV subunit vaccine and co-housed with two control animals. The animals were challenged 7 days later by intradermal injection in the tongue with 2 x 10 to the 4th power bovine infectious doses of homologous FMDV. Both control animals developed typical signs of FMD 2 days after challenge, including fever and vesicular lesions on all 4 feet and viremia for 2-3 days. All 5 vaccinated animals were protected from clinical disease, although one animal developed a lesion on the lip. None of the vaccinated animals had detectable viremia. Based on these results the Ad5-FMDV empty capsid vaccine could be used to control the spread of the virus in re-emerging situations.