Pertussis is a highly contagious respiratory illness caused by the bacterial pathogen Bordetella pertussis. Pertussis rates in the US have escalated since the 1990s and reached a 50-year high of 48,000 cases in 2012. While this pertussis resurgence is not completely understood, we previously showed that the current acellular pertussis vaccines do not prevent colonization or transmission following challenge. In contrast, a whole-cell pertussis vaccine accelerated the rate of clearance compared to unvaccinated and acellular vaccinated animals. In order to understand if these results are generalizable, we used our baboon model to compare immunity from whole-cell vaccines from three different manufacturers that are approved outside the US. We found that compared to no vaccine and acellular pertussis vaccine, immunization with any of the three whole-cell vaccines significantly accelerated the clearance of B. pertussis following challenge. Whole-cell vaccination also significantly reduced the total nasopharyngeal B. pertussis burden, suggesting that these vaccines reduce the opportunity for pertussis transmission. Meanwhile, there was no difference in either the duration or B. pertussis burden between unvaccinated and acellular pertussis-vaccinated animals, while previously infected animals were not colonized following re-infection. We also determined that transcription of the gene encoding IL-17 was increased in whole-cell vaccinated and previously infected animals, but not acellular pertussis vaccinated animals, following challenge. Together with our previous findings, these data are consistent with a role for Th17 responses in the clearance B. pertussis infection.
Authors:Warfel JM1, Zimmerman LI1, Merkel TJ2.
Journal:Clin Vaccine Immunol. 2015