Immunogenicity Issues in the Quality Control of the New Acellular Pertussis Vaccines

Over the last few years our laboratory has been assessing the consistency of production of different batches of acellular pertussis vaccines to be marketed in Italy. Central to this is immunogenicity assay of the lots under control compared with those of a reference vaccine with documented clinical efficacy.However, the current assays based on the assessment of antibody (Ab) response in the mouse are unrelated to mechanisms of protection in children. The absence of a clear correlation between Ab responses and protection has also been documented in recent clinical trials. On this basis, we are currently considering the possibility of adding to the established criteria of immunogenicity in mice based on Ab responses, information from studies on cell-mediated immune responses to the vaccine constituents.