Although Bordetella pertussis is considered the main causative agent of whooping cough in humans, Bordetella parapertussis infections are not uncommon. The widely used acellular whooping cough vaccines (aP) are comprised solely of B. pertussis antigens that hold little or no efficacy against B. parapertussis.
We show that aP vaccination helped clear B. pertussis but resulted in an approximately 40-fold increase in B. parapertussis lung colony-forming units (CFUs).
aP vaccination impedes host immunity against B. parapertussis…
aP vaccination interferes with the optimal clearance of B. parapertussis and enhances the performance of this pathogen. Our data raise the possibility that widespread aP vaccination can create hosts more susceptible to B. parapertussis infection.
Despite decades of worldwide pertussis vaccination, whooping cough is re-emerging in highly vaccinated countries.
[I]t is not clear how Bordetella parapertussis—the other major aetiological agent of human whooping cough—might respond to the selective pressure exerted by large-scale pertussis vaccination. Here, we postulate that the widespread and long-term use of acellular subunit pertussis vaccines creates hosts that are more favourable for B. parapertussis.
aP vaccines… hold little or no efficacy against B. parapertussis.
[W]e hypothesize that the prolonged and widespread use of B. pertussis-specific aP vaccines has the potential to increase carriage of species not included in the vaccine, namely B. parapertussis.
[W]hen differential diagnosis has been carried out, B. parapertussis was found to comprise between 2 and 36 per cent of cases and, in one study, to constitute the major aetiological agent.
Some aP vaccine efficacy studies report a significantly higher proportion of B. parapertussis relative to B. pertussis in aP-vaccinated compared with unvaccinated individuals.
aP vaccination significantly increased B. parapertussis CFU.
The average bacterial abundance produced throughout infection was approximately 40-fold higher in aP-vaccinated relative to sham-vaccinated hosts.