Validation of a Novel ELISA and Immunochromatography Assay for Tetanus Antibody Detection.

We developed a highly sensitive and reproducible enzyme-linked immunosorbent assay (ELISA) and a qualitative immunochromatography (IC) test to specifically measure antibodies against tetanus toxoid. These methods detect tetanus antibodies in human, mouse, rabbit, and horse sera. These assays demonstrated high accuracy and precision for mouse and human samples. Using the developed ELISA, we quantified tetanus antibody titers in a mouse immunization model (tetanus toxoid potency test) and in human samples. The relative potency of tetanus toxoid calculated from ELISA titers was comparable to that determined by the traditional in vivo toxin challenge method. In human pooled plasma, ELISA titers correlated strongly with neutralizing antibody titers (r = 0.9826), enabling the estimation of the latter. Furthermore, ELISA titers correlated highly with results from the Kaketsuken particle agglutination method (r = 0.9866) and the novel IC (r = 0.8209). These findings demonstrate the utility of these methods for evaluating vaccine efficacy and immune responses, suggesting broad applications in basic research and clinical settings.