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Background: Diphtheria and Tetanus are able to prevent as a combined vaccine that containing Diphtheria Toxoid (DT) and Tetanus Toxoid (TT) that are adsorbed on aluminum gel to boost the immune response. Therefore, the adsorption level of toxoids must be controlled according to the product specifications in order to ensure vaccine quality. The determination of degree adsorption of DT and TT in the combined vaccine was conducted by a Sandwich Enzyme-linked Immunosorbent Assay (ELISA) technique which was performed to be used as an analytical method.
Objectives: To be used as the determination of degree adsorption of Diphtheria Toxoid and Tetanus Toxoid in combined vaccine.
Methods: Validation method study of analyzing the adsorption level of DT and TT in combined vaccines by using Sandwich ELISA technique in parameters of accuracy, precision, robustness, specificity, linearity, Limits of Quantification (LOQ), and range.
Results: The results showed that the accuracy, precision, and robustness met the acceptance criteria. The specificity result of the method was compliance with the standard. The linearity yielded the correlation coefficient (r) greater than 0.99. The LOQ ranged from 1.72 to 880 mLf/mL for DT and 0.07 to 550 mLf/mL for TT. The range of DT concentrations was between 3.44 and 110 mLf/mL, while the range of TT concentrations was between 1.08 and 34.50 mLf/mL.
Conclusion: This assay was appropriate to be adopted as a nation standard method. The average adsorption degree of DT and TT from four lots of vaccines manufactured in 2019–2020 were more than 90%, and in accordance with product specifications.
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