A sensitive and specific serology test for evaluating potency of whole cell Pertussis vaccines

Whooping cough (pertussis) is a highly contagious respiratory disease caused by the Gram-negative bacterium, Bordetella
pertussis. In most of the world, infants receive a whole cell pertussis (wP) vaccine in conjunction with diphtheria and tetanus
(DTwP). With tens of millions of doses of DTwP administered globally each year, evaluation of vaccine potency is a critical
step for manufacturers toward vaccine release. First established in 1947 and still in use today, the Kendrick assay is the
method of evaluating wP potency. As a labor intensive and highly variable mouse intracerebral challenge protocol, the
Kendrick assay constitutes a bottleneck in DTwP vaccine release. There have been efforts to replace the Kendrick assay
with a pertussis serology potency test (PSPT) based on a whole pertussis bacteria ELISA, but the PSPT suffers from issues
of sensitivity and variability. Antigen Discovery, Inc. and Dr. Nicholas Mantis and colleagues at the Division of Infectious
Diseases, Wadsworth Center, New York State Department of Health are collaborating in an effort to develop a PSPT based
on discovery of new B. pertussis antigens that may serve as indicators of wP vaccine potency. In the proposed study, a B.
pertussis proteome microarray will be developed to identify serological markers associated with wP vaccine potency in
mice immunized with DTwP at full potency or degraded potency due to thermal stress. Pilot studies have already
demonstrated that certain antigen-specific IgG responses indicate vaccine stability, while others indicate instability. We
hypothesize that a B. pertussis proteomic screen of antisera from mice vaccinated with potent versus subpotent DTwP
preparations will reveal B. pertussis antigens that could serve as reliable potency indicators and, ultimately, serve as the
basis of a multiantigen array to replace the Kendrick assay. To accomplish this, mice will be immunized with DTwP either
stored according to protocol (4ºC) or subjected to an accelerated decay protocol by extreme thermal stress (60ºC , 80ºC or
100ºC for 60 min). Baseline and post-immunization sera will be tested using B. pertussis proteome microarrays to identify
IgG response associated with the mice’s ability to clear B. pertussis bacteria by 4 days after intranasal inoculation with
5x106 CFU of B. pertussis 18323. A sample-sparing multiplex Luminex-based PSPT prototype will then be developed using
the antigens identified as indicators of wP vaccine stability and/or instability. The prototype assay will be optimized,
qualified and tested in an independent set of sera from mouse DTwP immunization experiments with or without thermal
stress. If successful, we will follow with an SBIR Phase II study, where the prototype Luminex-based PSPT will be
transferred to a qualified ELISA or CLIA automated assay format and developed under all of the Quality Assurance and
Regulatory Affairs requirements for submission of the potency assay to regulatory bodies. In a path toward
commercialization, our novel antigen-specific PSPT will be of interest to members of the PSPT consortium within the
Developing Countries Vaccine Manufacturing Network (https://dcvmn.org/pspt-consortium/), which includes all of the
major manufacturers of wP-containing vaccines and expressed interest in replacing the Kendrick Test with a reliable PSPT.

Grant Number: 1R43AI195168-01
NIH Institute/Center: NIH
Principal Investigator: Joseph Campo