Epidemiological and immunological reasons for pertussis vaccination in adolescents and adults.

The resurgence of pertussis has been the subject of considerable debate. Hypotheses to explain increased reporting in developed countries have focused mainly on three aspects: (1) increased recognition of the disease in adolescents and adults; (2) waning of vaccine-induced immunity and (3) loss of vaccine efficacy due to an antigenic shift of Bordetella pertussis. Waning immunity after vaccination or natural infection combined with the absence of regular boosters either in the form of vaccine boosters or natural exposure to B. pertussis - due to the low circulation of the bacterium in well-immunized populations - has been suggested to explain this shift in the age distribution of pertussis. The highest incidence of the disease is currently reported among adolescents and adults who may additionally serve as the source of infection for susceptible infants. Immunological and epidemiological data indicates the need for a universal booster vaccination against pertussis for adolescents and adults.