ABSTRACT
The production of an effective bacterial vaccine relies heavily upon process reproducibility. Cultures of spore-forming bacteria used in the production of vaccines may be adequately maintained at 4°C but may lose antigenicity/toxicity if frozen or freeze-dried. Adhesion to a mucosal surface is usually the initial stage of pathogenesis for most bacterial diseases and in many cases this adhesion is mediated, at least as a primary point of contact, by long filamentous surface antigens called fimbriae. The ability of bacteria to vary the antigenic composition of specific components is a powerful means of avoiding the immune response. Care must also be exercised during the resuscitation and growth of inocula from toxigenic strains of bacteria. The production of effective bacterial toxoid vaccines relies upon the secretion of high levels of toxins by vaccine strains. The proteins responsible for iron uptake in vivo are potential vaccine components since they perform an essential growth function without which infection would cease.
