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An indirect enzyme-linked immunosorbent assay (ELISA) was developed to quantify tetanus antitoxin activity in guinea pig sera based on a previously calibrated standard. This test is proposed as an alternative to the traditional in vivo neutralization assay used for potency evaluation of tetanus vaccines. The accuracy, precision and linearity of our ELISA were determined. Both methods were used to evaluate 75 guinea pig sera and the results were compared by linear regression analysis. The individual immunological responses against different lots of tetanus vaccine were also studied. The ELISA showed an excellent accuracy, with recovery values between 90-110%; intra, inter and total-assay imprecision ranging around 10% and parallelism deviations below 10%. A high correlation was found between our ELISA and the in vivo neutralization assay (R²= 0,989). The seroprotection levels of the tetanus vaccines tested were over 83%. All those results indicate our ELISA is an excellent alternative procedure for potency testing of tetanus toxoid vaccines. [ABSTRACT FROM AUTHOR]

The adsorption of the antigens in adjuvated vaccines is an important variable in formulation evaluation. The present work shows the quantification results for the diphtheric and tetanus toxoid percentages of adsorption to aluminum hydroxide by determining protein concentration by Lowry and HPLC chromatographic separation. The results show an average adsorption higher than 99% for both active principles in the antidiphtheric-tetanus vaccine (DT), while the antidiphtheric-tetanuspertuss is vaccine (DTP) reached 92% for the diphtheric component and more than 96% for the tetanus toxoid one. [ABSTRACT FROM AUTHOR]