Title: Development of a DIVA skin test for use alongside BCG vaccination
Funder: Department for Environment, Food and Rural Affairs

Abstract: Description Policy relevance: The development of improved vaccines for cattle forms part of the Government’s comprehensive eradication strategy for bTB. To enable BCG vaccination to be used alongside conventional test and slaughter control policy, a BCG compatible DIVA test is required. During previous projects, DIVA skin test (DST) reagents based on recombinant proteins of antigens not recognised by animals vaccinated with BCG have been developed. Before the DST can be granted a Marketing Authoristion it needs to be assessed in field trials. As a pre-requisite for such trials, an Animal Test Certificate (ATC) is required for the DST to enable them to proceed. Thus, the overall aim of this project is to compile and submit a dossier containing the relevant information required for the application of an ATC to the Veterinary Medicines Directorate (VMD) for the DST. This dossier will need to include several streams of information on the DST, including: (i) performance data; (ii) manufacturing data; (iii) safety data; and (iv) outline of a field trial protocol.Aims: In this proposal we detail the work that is required to generate the necessary data to support this ATC application, and then to draft this document. In the first objective, we will compare the relative performance of two DST formulations, namely a cocktail of the three protein antigens (DST-C) or a single fusion protein of the three proteins linked together (DST-F). Although the two different formulations are not expected to show significantly different antigenic properties, there may be some differences in the manufacturing process and stability of the product which may confer advantages to one over the other. In the second objective, we will review the current manufacturing procedures for the two formulations and agree a programme of work with commercial suppliers with an aim to satisfy the regulatory requirements for an IVMP (immunological veterinary medicinal product) for an ATC application, including establishing production and quality control protocols, assessing product stability and defining a strategy working towards commercial GMP manufacture. The results of these first two objectives will inform the decision on which formulation to progress to the ATC application. In the third objective, we will design and perform a GLP study to generate the necessary safety data for the selected DST reagent. Lastly, in the fourth objective we will prepare an outline protocol for a field trial evaluation of the selected DST reagent and draft the ATC application ready for submission to the VMD. Outputs: At the completion of this project we will have a dossier containing the necessary information required for submission to the VMD for an ATC for use of the chosen DST formulation in field trials. Objective Overall aim: Prepare an ATC application for the DST.Specific objectives:1. Generate DST performance data for inclusion into the ATC application.2. Generate DST manufacturing data for inclusion into the ATC application.3. Generate DST safety data for inclusion into the ATC application.4. Write the ATC application for the DST for submission to the VMD.


Research activity codes: 3.4 VACCINES
Health categories: INFECTION