What Is Wrong with Pertussis Vaccine Immunity? Inducing and Recalling Vaccine-Specific Immunity

Abstract

The high incidence of pertussis in vaccinated adolescents suggests the failing of immune memory. We argue that acellular pertussis vaccines generate memory cells that are effectively reactivated by boosters better than by Bordetella pertussis exposure. We propose that there are two main causes. One is the induction of vaccine-specific immunity rather than pathogen-specific immunity. The second is that strictly mucosal infections such as B. pertussis poorly reactivate memory B and T cells residing deep in lymph nodes or tissues. Developing new vaccines for infants or adolescents will be immunologically and economically challenging. Let us hope that maternal and infant immunization, to date the most effective strategies against pertussis death, will remain so.

Figure 1.

Pertussis toxin B-cell responses to primary and booster acellular pertussis (aP) immunizations or following exposition to Bordetella pertussis. Immune response to priming with aP (A) leads to formation of anti-pertussis toxin (PT) memory B cells. These are directed either against the epitopes unique to denatured PT (red) or of wild-type PT (blue). Upon boosting (B), the proportion of anti-PT memory B cells specific to wild-type PT declines proportionally to the increasing number of doses (and thus age). Consequently, fewer and fewer wild-type PT-specific B cells are available for reactivation at time of exposure to B. pertussis (C).