An Immunogenicity and Safety Study of Tetanus, Diphtheria and Acellular Pertussis Vaccine Booster

Inclusion Criteria: * healthy subject * 14-15 years old * eligible for their school-leaving booster for DTP * received a complete primary vaccination with a 5-component acellular pertussis vaccine (DT5aP-IPV-Hib) at 3, 5 and 12 months of age and vaccinated with a 5-component acellular pertussis vaccine (Td5aP-IPV or Td5aP + IPV) as a booster at 5½ years of age * informed consent form signed by the subject and parent(s)/legal representative * subject understand and comply with the study procedures (i.e. able to read and write Swedish) * female must provide an agreement that they are either sexually continent or practice adequate contraceptive methods (intra-uterine contraceptive device (IUCD), hormonal contraceptives, condoms or other adequate barrier contraception). Exclusion Criteria: * acute febrile illness or axillary temperature ≥38.0°C at the time of vaccination * receipt of immunoglobulin within the previous 3 months, immunosuppression (e g evidence of impaired cell mediated immunity, receipt of immunosuppressant drugs within the previous 3 months or receipt of systemic corticosteroids given daily or on alternate days at ≥20 mg/day prednisone equivalent during \>14 days within the past 30 days) * receipt of a non-study vaccine in the past 30 days * evolving encephalopathy not attributable to another identifiable cause within 7 days of administration of a previous dose of any vaccine * booster vaccination with tetanus, low dose diphtheria and acellular pertussis vaccine since the booster vaccination at 5½ years of age * previous clinical or bacteriological diagnosis of diphtheria, tetanus or pertussis * hypersensitivity to any component of any of the study vaccines * current participation in any other clinical trial or participation in any clinical trial in the previous month * inability to adhere to the protocol, including plans to move from the area * severe chronic disease * family history of congenital or hereditary immunodeficiency * any sever thrombocytopenia or any other coagulation disorder that would contraindicate intramuscular injection * any medical condition, which in the opinion of the investigator, might interfere with the evaluation of the study objectives.