Overview of the clinical development of a diphtheria-tetanus--acellular pertussis vaccine

A tricomponent acellular pertussis vaccine containing pertussis toxoid, filamentous hemagglutinin, and pertactin combined with diphtheria and tetanus toxoids (DTPa) was developed as a less reactogenic alternative to the traditional whole cell pertussis (DTPw) vaccine. In studies of DTPa as a primary vaccination and as a booster dose in DTPa- or DTPw-primed children, the vaccine was safe, well-tolerated, and highly immunogenic; it was less reactogenic than DTPw but at least as immunogenic. A three-dose primary vaccination sequence with DTPa vaccine in the first 6 months of life protects against pertussis under conditions of high infectious pressure. These results support the licensing of the vaccine for primary and booster vaccination in a growing number of countries. Combined DTPa-based pediatric vaccines are in clinical development.