ABSTRACT
This chapter aims to consider new approaches to the potency assessment of vaccines against foot and mouth disease (FMD), giving rise to methodology that also might possibly be applicable to other vaccines. A timecourse model is described that has useful properties. It is described based on a single differential equation for antibody of affinity K, with equations collected together over all clones. Antibody levels are obtained, as a routine adjunct to the challenge test, in the form of neutralization test titres. A model for antibody levels has been defined which is based on the ideas of clonal selection and, it is hoped, proves simple enough to fit to immunoassay data. The model has been used to simulate immune profiles of antibody responses to FMD vaccine, using appropriate parameter values. The timecourse model is heavily dependent upon the concept of the affinity density.
