Immunogenicity and Safety of BoostrixTM Using a New Syringe in 10 to 15-year Old Adolescents

Inclusion Criteria: * Subject's parent(s)/Legally Acceptable Representative(s) and subjects who the investigator believes can and are willing to comply with the requirements of the protocol. * A male or female between 10 and 15 years of age at the time of booster vaccination. * Prior to protocol amendment 2, subjects who have previously received 5 doses of diphtheria-tetanus-pertussis vaccine (whole cell/acellular \[w/a\]) as part of primary and booster vaccination, in line with local recommendations. * After protocol amendment 2, subjects who have previously received 6 doses of either DT(P) (w/a)/ dTpa vaccine as part of primary and booster vaccination, in line with local recommendations. * Healthy subjects as determined by the investigator based on medical history and clinical examination before entering into the study. * Written informed consent to be obtained before study entry from the parent(s)/ Legally Acceptable Representative(s) of the subject. * Written informed assent to be obtained from the subject in addition to the informed consent signed by the parent(s)/ Legally Acceptable Representative(s), if required by local regulations. * Female subjects of non-childbearing potential may be enrolled in the study. * Female subjects of childbearing potential may be enrolled in the study, if the subject: * has a negative pregnancy test on the day of vaccination, * if sexually active, has practiced adequate contraception for 30 days prior to vaccination, and has agreed to continue adequate contraception during the entire treatment period and for 2 months after booster vaccination. Exclusion Criteria: * Child in care. * Use of any investigational or non-registered product other than the study vaccine within 30 days preceding the booster dose of study vaccine, or planned use during the study period. * Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the booster dose. * Planned administration/administration of a vaccine not foreseen by the study protocol within 30 days of the booster dose of vaccine - with the exception of influenza vaccine which is allowed up to 7 days before the study vaccine dose, or planned in the period ≥ 7 days after the study vaccine dose. * Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational product. * A history of previous or intercurrent diphtheria, tetanus or pertussis disease. * A history of vaccination against these diseases since the 5th or the 6th dose of DT(P)/dT(pa). For subjects who have received the 6th dose of the diphtheria, tetanus and/or pertussis containing vaccine, the interval between the last DT(P)/dT(pa) vaccination and the administration of the study vaccine should be at least 18 months. * Occurrence of any of the following adverse event after a previous administration of a Boostrix vaccine : * known hypersensitivity to any component of the vaccine, or have shown signs of hypersensitivity after previous administration of diphtheria, tetanus or pertussis vaccines, * encephalopathy of unknown aetiology occurring within 7 days following previous vaccination with pertussis-containing vaccine, * transient thrombocytopenia or neurological complications following an earlier immunisation against diphtheria and/or tetanus. * Any confirmed or suspected immunosuppressive or immunodeficient condition, based on medical history and physical examination. * History of any reaction or hypersensitivity likely to be exacerbated by any component of the vaccine. * Administration of immunoglobulins and/or any blood products within the 3 months preceding the first dose of study vaccine or planned administration during the study period. * Acute disease and/or fever at the time of enrolment. * Pregnant or lactating female. * Female planning to become pregnant or planning to discontinue contraceptive precautions, if applicable.