Determination of Analytical Method Validation for Indirect ELISA Quantification of Antibody Titer against PT Antigen in Acellular Pertussis Vaccine Using Mouse Immunogenicity Test

Abstract

Acellular pertussis vaccines are contained pertussis toxin (PT) as a major active substrate
component, which are produced in Thailand. Then, the researchers developed a method for
determination of the anti-PT antibody titer used to control the potency of the vaccine using
mouse immunogenicity test (MIT). The MIT is a non-lethal animal model designed to evaluate
antibody responses in immunized mice to the PT antigen claimed to contribute to vaccine
efficacy by ELISA technique. The validation method showed a good specification by separation
of anti-PT antibody titer between vaccine test group and negative control group. The linearity
was found at the range of anti-PT antibody titer from 1.95 to 4000.00 mIU/mL, with the coefficient
of correlation and the coefficient of determination were greater than 0.99. The lower limit of
quantitation was 1.95 mIU/mL and the upper limit of quantitation was 4,000.00 mIU/mL. The
range ranged from 7.81 to 500.00 mIU/mL. The accuracy had the percentage relative error (%RE)
between -2.11 to 2.37%. The precision varied from 5.57 to 11.51 percentage of variance
coefficient (%CV). The method was robust to the test system and analyzers, %CV was 6.47 to
9.08. Based on the validation results, the method demonstrates that the method is reliable
and suitable. It can be used as a standard method for the detec tion of anti-PT antibody to
effectively control the quality of acellular pertussis vaccine.