Pertussis is still a major Public Health problem. In fact, despite high vaccination coverage, several outbreaks have occurred in the last years all over the world, with thousands of cases and several deaths. Waning immunity seems to be the origin of this phenomenon, causing the shift of the peak incidence of the disease from school-age children, typical of the pre-vaccination era, to adolescents and adults. From these subjects the infection spreads to infants who have not yet been vaccinated or who have not completed the vaccination cycle. To reduce the incidence and the complications of pertussis in infants and immune compromised persons, booster doses are recommended and a "cocoon" vaccination strategy has been proposed.