Since several years, pertussis has increased especially in non-immunized young infants under 6 months of age, in countries where pertussis-immunization is in widespread use. The whole-cellular pertussis vaccine so far used in these countries is not well tolerated, has been indicted in adverse neurological complications, and offers significant but temporary protection partially because of the absence of late booster-shots. The necessity to improve vaccine protection has justified the development of much better tolerated acellular pertussis vaccines thus allowing repeated booster-shots. Its safety and duration of protection are still under evaluation, but preliminary results are promising.