Antibody persistence 2 and 3 years after booster vaccination of adolescents with recombinant acellular pertussis monovalent aP or combined TdaP vaccines.

Background: Recombinant pertussis vaccines inducing long-lasting immune responses could help to control the rise in pertussis. We here report on persisting antibody responses 2 and 3 years after booster vaccination with a new generation recombinant acellular pertussis vaccine.

Methods: Participants of a phase 2/3 randomised-controlled clinical trial with a monovalent pertussis vaccine containing genetically inactivated pertussis toxin (aP) or its tetanus and diphtheria toxoids combination (TdaP), or a chemically detoxified comparator vaccine (Tdap), (originally conducted between July and August 2015) were invited to participate in observational studies of persisting antibody responses 2 and 3 years after vaccination.

Antibody persistence after vaccination of adolescents with monovalent and combined acellular pertussis vaccines containing genetically inactivated pertussis toxin: a phase 2/3 randomised, controlled, non-inferiority trial.

Background: The immunogenicity of acellular pertussis vaccines and persistence of immunity after vaccination might be improved by using genetically inactivated pertussis toxin (PTgen) instead of chemically inactivated pertussis toxin (PTchem) because of the preservation of conformational epitopes. We assessed the safety and immunogenicity of two vaccines containing PTgen 1 year after vaccination.

Methods: We did a phase 2/3 non-inferiority, randomised, controlled trial involving 450 adolescents (age 12-17 years) enrolled between July 6, 2015, and Aug 20, 2015.

A genetically inactivated two-component acellular pertussis vaccine, alone or combined with tetanus and reduced-dose diphtheria vaccines, in adolescents: a phase 2/3, randomised controlled non-inferiority trial.

Background: Increasing evidence shows that protection induced by acellular pertussis vaccines is short-lived, requiring repeated booster vaccination to control pertussis disease. We aimed to assess the safety and immunogenicity of a recombinant acellular pertussis vaccine containing genetically inactivated pertussis toxin and filamentous haemagglutinin, as either a monovalent vaccine (aP) or in combination with tetanus and reduced-dose diphtheria vaccines (TdaP), versus a licensed tetanus and reduced-dose diphtheria and acellular pertussis combination vaccine (Tdap).

Methods: We did this phase 2/3, randomised controlled non-inferiority trial at two sites in Bangkok, Thailand.