Characterisation of monoclonal antibodies against foot-and-mouth disease vaccine strain C1 Oberbayern and their reactivity with field isolates

The antigenicity of FMDV can change because of frequent mutations in it's genome, and thus evade the immunity provided by vaccines. It is therefore necessary to monitor the field isolates for their relatedness to vaccine strains to ensure that currently available vaccine will provide protection against any new isolate. Currently, an ELISA based on the use of polyclonal hyperimmune serum is used by the WRL for FMD for the antigenic profiling of field isolates. However, the inherent variation in the properties of polyclonal serum batches complicates the interpretation of results. An antigen profiling ELISA, based on monoclonal antibodies (MAbs) has also been described (Samuel et. al., 1991). We aim to refine this approach in order to have a more reliable ELISA that could ultimately alleviate the need for in-vivo testing of selected vaccine strains. As a first step towards this goal, we have started production and characterisation of monoclonal antibodies to cover the entire antigenic spectrum of vaccine strains held by the IVB. In this report results are presented of studies that have been done with the C1 Oberbayern vaccine strain of FMDV.