Evaluation of GlaxoSmithKline Biologicals' Boostrix® Vaccine in Comparison With Decavac™ Vaccine.

• Number of Subjects With Antibody Concentration Against Vaccine Antigens, Above a Protocol Defined Cut-off Value [ Time Frame: One month after vaccination. ]

  Antibodies against vaccine antigens assessed were: anti-diphtheria (anti-D) and anti-tetanus (anti-T).

  Anti-D antibody cut-off value assessed was ≥ 0.1 International Unit per milliliter (IU/mL)

  Anti-T antibody cut-off values assessed were ≥ 0.1 IU/mL and ≥ 1.0 IU/mL

• Anti-pertussis Toxoid (PT), Anti-filamentous Haemagglutinin (FHA) and Anti-pertactin (PRN) Antibodies Concentration [ Time Frame: Before (PRE) and one month after vaccination (POST) ]
  Concentration for anti-PT, anti-FHA and anti-PRN antibodies given as geometric mean concentration (GMC) in Enzyme-Linked Immuno Sorbent Assay (ELISA) units per millilitre (EL.U/mL)

• Anti-T and Anti-D Antibody Concentrations [ Time Frame: Before (PRE) and one month after vaccination (POST) ]
  Concentrations for anti-T and anti-D antibodies given as GMC in IU/mL.
• Number of Subjects With Vaccine Response for Anti-T and Anti-D Antibodies Concentrations Above the Cut-off [ Time Frame: One month after vaccination ]

  Booster response defined as :

  For initially seronegative subjects (< 0.1 IU/mL), antibody concentration ≥ 0.4 IU/mL one month after vaccination.

  For initially seropositive subjects (≥ 0.1 IU/mL): antibody concentration one month after vaccination ≥ 4 fold the pre-vaccination antibody concentration.

• Number of Subjects With Vaccine Response for Anti-PT, Anti-FHA and Anti-PRN Antibodies Concentrations Above the Cut-off [ Time Frame: One month after vaccination ]

  Booster response defined as :

  For initially seronegative subjects (< 5 EL.U/mL), antibody concentration ≥ 20 EL.U/mL one month after vaccination.

  For initially seropositive subjects (≥ 5 EL.U/mL) with pre-vaccination antibody concentration < 20 EL.U/mL: antibody concentration one month after vaccination ≥ 4 fold the pre-vaccination antibody concentration.

  For initially seropositive subjects (≥ 5 EL.U/mL) with pre-vaccination antibody concentration ≥ 20 EL.U/mL : antibody concentration one month after vaccination ≥ 2 fold the pre-vaccination antibody concentration.

• Number of Subjects With Vaccine Response for Anti-PT, Anti-FHA and Anti-PRN Antibodies Concentrations Above the Cut-off, Using Alternative Definitions. [ Time Frame: One month after vaccination ]

  Vaccine response defined as:

  For initially seronegative subjects (< 5 EL.U/mL ), antibody concentration ≥ 10 EL.U/mL one month after vaccination.

  For initially seropositive subjects (≥ 5 EL.U/mL), antibody concentration one month after vaccination ≥ 2 fold the pre-vaccination antibody concentration.

• Number of Subjects Reporting Solicited Local Symptoms [ Time Frame: Within the 4-day (Day 0-3) post-vaccination period ]
  Solicited local symptoms assessed include pain, redness and swelling.
• Number of Subjects Reporting Solicited General Symptoms [ Time Frame: Within the 4-day (Day 0-3) post-vaccination period ]
  Solicited general symptoms assessed include fatigue, gastrointestinal symptoms, headache, and fever
• Number of Subjects Reporting Unsolicited Adverse Events (AE) [ Time Frame: Within the 31-day (Day 0-30) post-vaccination period ]
  An AE is any untoward medical occurrence in a clinical investigation subject, temporally associated with the use of a medicinal product, whether or not considered related to the medicinal product.
• Number of Subjects Reporting Serious Adverse Events (SAE) [ Time Frame: From the vaccintation up to Day 182 ]
  An SAE is any untoward medical occurrence that: results in death, is lifethreatening, requires hospitalization or prolongation of existing hospitalization, results in disability/incapacity, is a congenital anomaly/birth defect in the offspring of a study subject, or may evolve into one of the outcomes listed above.

• Immunogenicity of study vaccine antigens. [ Time Frame: One month after vaccination. ]
• Booster responses of study vaccine antigens. [ Time Frame: One month after vaccination. ]
• Booster responses to study vaccine antigens using alternative definitions. [ Time Frame: One month after vaccination ]
• The occurrence of solicited local symptoms during the follow-up period after vaccination. [ Time Frame: 4-days following vaccination. ]
• The occurrence of solicited general symptoms during the follow-up period after vaccination. [ Time Frame: 4-days following vaccination. ]
• The occurrence of unsolicited symptoms during the days following vaccination. [ Time Frame: 31-days following vaccination. ]
• The occurrence of Serious Adverse Events (SAEs) during the active phase and extended safety follow-up phase. [ Time Frame: 31 days and 6 months following vaccination. ]

• Tetanus
• Acellular Pertussis
• Diphtheria

• Biological: Boostrix®
  Intramuscular, single dose.
• Biological: Decavac™
  Intramuscular, single dose.

• Experimental: Boostrix Group
  Subjects received a single dose of Boostrix™ (tetanus toxoids, reduced diphtheria toxoids and acellular pertussis vaccine)
  Intervention: Biological: Boostrix®
• Active Comparator: Decavac Group
  Subjects received a single dose of Decavac™ (tetanus and diphtheria toxoids vaccine)
  Intervention: Biological: Decavac™

• Weston WM, Friedland LR, Wu X, Howe B. Vaccination of adults 65 years of age and older with tetanus toxoid, reduced diphtheria toxoid and acellular pertussis vaccine (Boostrix(®)): results of two randomized trials. Vaccine. 2012 Feb 21;30(9):1721-8. doi: 10.1016/j.vaccine.2011.12.055. Epub 2011 Dec 31.
• Weston WM et al. Vaccination of adults 65 years of age and older with tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine (Boostrix™): results of a randomized clinical trial. Abstract presented at the 45th National Immunization Conference (NIC). Washington, USA, 28-31 March 2011.

Inclusion Criteria:

• Subjects who the investigator believes that can and will comply with the requirements of the protocol should be enrolled in the study.
• Males or females 65 years of age and older at the time of study entry.
• Free of an acute aggravation of the health status as established by medical history and medical history and clinical examination before entering into the study.
• Written informed consent from all subjects.

Exclusion Criteria:

• Administration of a diphtheria-tetanus (Td) booster within the previous 5 years.
• Administration of a Tdap vaccine at any time prior to study entry.
• History of diphtheria and/or tetanus and/or pertussis disease.
• Use of any investigational or non-registered drug or vaccine other than the study vaccines within 30 days preceding vaccination, or planned use during the entire study period.
• Administration of other licensed vaccines within 2 weeks (for inactivated vaccines) or 4 weeks (for live vaccines) prior to enrolment in this study, with the exception of influenza, vaccine, which may be administered at any time up to or during the study period, including the day of study vaccination.
• Planned administration of any vaccine not foreseen by the study protocol up to 30 days following vaccination, with the exception of influenza, vaccine, which may be administered at any time up to or during the study period, including the day of study vaccination. Pneumococcal and zoster vaccines can be administered at the discretion of the investigator when the subject comes back at Visit 2.
• Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to vaccination or planned administration during the study period.
• Any confirmed or suspected immunosuppressive or immunodeficient condition based on medical history and physical examination.
• History of serious allergic reaction following any other tetanus toxoid, diphtheria toxoid or pertussis-containing vaccine or any component of the study vaccines.
• History of encephalopathy within seven days of administration of a previous booster dose of pertussis vaccine that is not attributable to another identifiable cause.
• Progressive neurologic disorder, uncontrolled epilepsy or progressive encephalopathy: pertussis vaccine should not be administered to individuals with these conditions until a treatment regimen has been established and the condition has stabilized.
• Acute (active) clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by clinical evaluation or pre-existing laboratory screening tests.
• Acute disease at the time of vaccination.
• Administration of immunoglobulins and/or any blood products within the three months preceding vaccination, or planned administration during the study period.
• Any medical condition that, in the opinion of the investigator, might interfere with the evaluations required by the study.