Location: Foreign Animal Disease Research2013 Annual Report
1a. Objectives (from AD-416):
This project will establish collaborative research with two institutions of the Indian Council of Agricultural Research working on FMD to conduct antigenic and genetic characterization of FMD field virus isolates, surveillance, monitoring and vaccine strain selection for FMD control programs in India.
1b. Approach (from AD-416):
Researchers from ARS, the Indian Veterinary Research Institute, and the Project Directorate on Foot and Mouth Disease (PDFMD) will: i) genetically and serologically characterize FMDV strains from cattle, buffalo and sheep circulating in endemic areas of India; ii) utilize phylogenetic and serological studies to determine the serological relationship of FMDV strains and identify viral strains conferring cross reaction against a wide range of subtypes within FMD serotypes; and iii) utilize the hAd5-vector platform to generate candidate vaccines containing the P1 region of the Indian vaccine strains (Serotypes O,A and Asia1) and any other widely reactive Indian field strains and test in pilot proof of concept experiment the serological response of animals vaccinated with the novel hAd5-FMD vaccines compared to current vaccines strains.
3. Progress Report:
During FY 2013, scaled up and purified the Ad5-FMD recombinant vaccines and conducted a trial in Indian cattle with monovalent as well as trivalent Ad5 vaccines. Three recombinant Ad5 viruses engineered to express capsid proteins of Indian FMD vaccine virus strains, O, A and Asia 1, were scaled up and purified. The seed viruses used for scaling up were tested for FMD virus type specificity using sandwich ELISA test. The results confirmed that each of the recombinant viruses expressed only the capsid protein of the serotype for which they carry nucleotide sequences. This is the first time that sandwich ELISA was used for detecting type specificity of FMD capsid protein expressed through Ad5 virus vector. Seroconversion studies were conducted on FMDV seronegative cattle. The animals (6 per group) were inoculated with Ad5-FMDV monovalent or Ad5-FMDV trivalent vaccine, or vector control Ad5-Blue virus or inactivated oil adjuvanted trivalent vaccine obtained from a local commercial vaccine manufacturer. The neutralzing antibody response was measured. Results showed different levels of seroconversion for the three FMD serotypes with 5/6, 4/6 and 2/6 sropositive animald for O, A and Asia1 serotypes respectively. In trivalent formulation the Ad5-FMD group showed detectable levels of antibodies with 1/6 and 2/6 animals for type O andA respectively. None of the animals responded for type Asia-1. All the animals vaccinated with inactivated trivalent vaccine sero-converted against all the three types of FMD virus. Following booster immunization in monovalent Ad5-FMD groups and inactivated vaccine groups, a significant increase in neutralizing antibody response was noticed when sera collected on days 14 and 28 were tested. Booster inoculations of the Ad5-FMD monovalent groups resulted in increased antibody responses. No technologies were transferred or publications produced during FY 2013.