The Pertussis Serological Potency Test. Collaborative study to evaluatereplacement of the Mouse Protection Test

Area of Science:

• * Immunology
• * Vaccinology
• * Microbiology

Background:

• * The Mouse Protection Test (MPT) is the standard for pertussis vaccine potency testing.
• * An in vitro alternative, the Pertussis Serological Potency Test (PSPT), was developed.
• * PSPT assesses the humoral immune response against Bordetella pertussis.

Purpose of the Study:

• * To evaluate the relevance and reliability of the PSPT in a collaborative study.
• * To compare PSPT with the established MPT.
• * To assess the performance of the 18323-whole cell ELISA (WCE) assay.

Main Methods:

• * A collaborative study involving five laboratories.
• * Three phases: pilot study of 18323-WCE, Phase I for precision, Phase II for comparative analysis.
• * Assessed intra-assay, inter-assay, and inter-laboratory precision of 18323-WCE.

Main Results:

• * Significant differences in absorbance and antibody concentrations were observed between laboratories.
• * Despite variations, antibody ranking in the 18323-WCE assay showed good inter-laboratory correlation.
• * Vaccine potencies estimated by PSPT and MPT did not differ significantly; PSPT demonstrated higher reproducibility.

Conclusions:

• * The Pertussis Serological Potency Test (PSPT) is a valid and reliable in vitro method for estimating pertussis whole cell vaccine (WCV) potencies.
• * The 18323-WCE assay is easy to perform and provides reliable potency testing.
• * PSPT offers improved reproducibility and reduced re-testing compared to MPT.