Robust Humoral and Cellular Immune Responses to Pertussis in Adults After a First Acellular Booster Vaccination

Abstract

IntroductionTo reduce the pertussis disease burden, nowadays several countries recommend acellular pertussis (aP) booster vaccinations for adults. We aimed to evaluate the immunogenicity of a first adult aP booster vaccination at childbearing age.MethodsIn 2014, healthy adults aged 25–29 years (n = 105), vaccinated during infancy with four doses of whole-cell pertussis (wP) vaccine, received a Tdap (tetanus, diphtheria, and aP) booster vaccination. Blood samples were collected longitudinally pre-booster, 2 and 4 weeks, and 1 year and 2 years post-booster. Tdap vaccine antigen-specific antibody levels and memory B- and T-cell responses were determined at all time points. Antibody persistence was calculated using a bi-exponential decay model.ResultsUpon booster vaccination, the IgG levels specific to all Tdap vaccine antigens were significantly increased. After an initial rapid decline in the first year, PT-IgG antibody decay was limited (15%) in the second year post-booster. The duration of a median level of PT-IgG ≥20 IU/mL was estimated to be approximately 9 years. Vaccine antigen-specific memory B- and T-cell numbers increased and remained at high levels although a significant decline was observed after 4 weeks post-booster. However, Th1, Th2, and Th17 cytokine production remained above pre-booster levels for 2 years.ConclusionThe Tdap booster vaccination in wP-primed Dutch adults induced robust long-term humoral and cellular immune responses to pertussis antigens. Furthermore, PT-IgG levels are predicted to remain above the presumed protective cut-off for at least 9 years which might deserves further attention in evaluating the current recommendation to revaccinate women during every new pregnancy.

Circulation of pertussis and poor protection against diphtheria among middle-aged adults in 18 European countries

“…However, only a high country-wide coverage of these boosters might have a significant influence on the pertussis incidence. Moreover, there is evidence that the immunogenicity of repeated aP boosters seems to diminish, although the persistence of aP vaccine-induced antibodies after a first booster in wP-primed adults appeared to be longer compared to children 25 . Furthermore, many studies have shown the kinetics of anti-PT IgG antibodies and how they quite rapidly wane after vaccination or even after infection, although more prolonged 26 – 28 .…”

Th1/Th17 polarization persists following whole-cell pertussis vaccination despite repeated acellular boosters

“…Indeed, stronger IL-17 polarization from wP vaccination has been reported to be associated with higher protection in baboon models (15,26,27,44) and to be pivotal in the mediation of adaptive immunity by tissue-resident memory T cells after natural infection in mice (45,66). Although IL-17 has been detected in supernatants of PBMCs stimulated with pertussis antigens (67,68), to the best of our knowledge, this is the first time that CD4 + T cells secreting both IL-9 and IL-17 have been shown to be associated with pertussis-specific responses after wP or aP vaccination regimens in humans.…”

Antibody responses to Bordetella pertussis and other childhood vaccines in infants born to mothers who received pertussis vaccine in pregnancy – a prospective, observational cohort study from the United Kingdom

“…No correlate of protection has been defined for pertussis ; however, high antibody levels are important . Several papers have used arbitrary thresholds when analysing pertussis antibody levels , and thus for our analysis we utilised the commonly used arbitrary threshold of ≥20 IU/ml for PTx, FHA and Prn antibody concentrations. A significantly higher percentage of infants from vaccinated pregnancies reached these antibody levels for tetanus and diphtheria, and the arbitrarily defined threshold for pertussis antibody in the first 7 weeks of life, compared to infants born from unvaccinated mothers.…”