Restricted antibody response to Bordetella pertussis filamentous hemagglutinin induced by whole-cell and acellular pertussis vaccines

Abstract

Background: Filamentous hemagglutinin (FHA) is a principal virulence factor, an important immunogenic antigen of Bordetella pertussis, and a major component of many acellular pertussis vaccines. In the present study, the human antibody response to different regions of FHA was determined in healthy children and adults vaccinated with either whole-cell or acellular pertussis vaccines. Methods: To define the immunodominant regions of FHA, four overlapping recombinant fragments were expressed and produced in Escherichia coli and then purified by His-tagged based affinity chromatography. Two groups comprising healthy preschool children (n = 50) and adults (n = 26) were vaccinated with a single dose of commercial whole-cell and acellular DTaP vaccines, respectively. An antigen-based ELISA was applied to measure serum levels of anti-FHA antibody to both native and recombinant proteins in vaccinated volunteers. Results: In both groups of vaccinated individuals, the anti-FHA antibody response was mainly directed against epitopes located within a fragment of FHA spanning amino acid residues 1877–2250 of the mature FHA molecule (p < 0.001). No or little antibody was detected against the other recombinant segments of FHA. Conclusion: Our results suggest that the human antibody response to FHA is directed to an immunodominant region located within residues 1877–2250 of the FHA molecule. Characterization and epitope mapping of the major components of acellular pertussis vaccine and future modifications in vaccine formulation may improve its efficacy and protectivity.

Keywords:

• Filamentous hemagglutinin
• Bordetella pertussis
• whole-cell pertussis vaccine
• acellular pertussis vaccine

Acknowledgments

This study was supported by grants from the Ministry of Health and Medical Education of Iran and Avicenna Research Institute.

Declaration of interest

The authors report no conflict of interests. The authors alone are responsible for the content and writing of the paper.