The aim of the study is to assess the immunogenicity and safety profile of ADACEL compared to local adsorbed diphtheria and tetanus combined vaccine (local DT or local Td vaccine in participants in China.

Primary objective:

• To describe diphtheria and tetanus seroprotection rates and pertussis booster response rates induced by each of the study vaccines: ADACEL vaccine (in all study age groups), local DT vaccine (in children), and local Td vaccine (in adolescents and adults).

Secondary Objectives:

• To further describe in each group the immunogenicity of the study vaccines at baseline and 1 month after vaccination.
• To describe the safety of the study vaccines

Study participants will receive a single booster dose of ADACEL (Tdap vaccine) or a single booster dose of local DT or local Td vaccine, depending on the age subgroup.

Immunogenicity will be assessed before and 28 days post-vaccination; safety profile will be assessed in all subjects up to Day 35 post vaccination.

Inclusion Criteria:

• Aged 4 through 64 years on day of inclusion
• For children and adolescents (4 through 17 years): Informed consent form has been signed and dated by the parent(s) or another legally acceptable representative and assent form has been signed and dated by the subject if aged 8 through 17 years

For adults (18 years and over): Informed consent form has been signed and dated by the subject

• Subject and parent / legally acceptable representative (for subjects up to 17 years) are able to attend all schedule visits and to comply with all trial procedures
• According to China National Immunization Recommendations, written documentation of complete primary series and fourth dose of diphtheria, tetanus, pertussis (DTP) vaccine for subjects aged 4 through 7 years and a written documentation or oral confirmation of complete primary series and fourth dose of DTP vaccine for subjects aged 8 through 64 years

Exclusion Criteria:

• Participation at the time of study enrollment (or in the 4 weeks preceding the first trial vaccination) or planned participation during the present trial period in another clinical trial investigating a vaccine, drug, medical device, or medical procedure.

• Receipt of any vaccine in the 4 weeks preceding the trial vaccination or planned receipt of any vaccine in the 4 weeks following the trial vaccination.

• Previous vaccination against diphtheria and tetanus disease with either the trial vaccine or another vaccine (except Tetanus-prone wound management for adults) in the past 12 months.

• Previous fifth vaccination against pertussis disease.

• Receipt of immune globulins, blood or blood-derived products in the past 3 months.

• Known or suspected congenital or acquired immunodeficiency; or receipt of immunosuppressive therapy, such as anti-cancer chemotherapy or radiation therapy, within the preceding 6 months; or long-term systemic corticosteroid therapy.

• Known (laboratory-confirmed / self-reported) Human Immunodeficiency Virus (HIV) or Hepatitis C seropositivity.

• History of diphtheria, tetanus, or pertussis infection (confirmed either clinically, serologically or microbiologically).

• Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccines used in the trial or to a vaccine containing any of the same substances.

• Laboratory-confirmed / self-reported thrombocytopenia, contraindicating intramuscular vaccination.

• Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating intramuscular vaccination.

• Deprived of freedom by an administrative or court order, or in an emergency setting, or hospitalized involuntarily.

• Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion.

• Moderate or severe acute illness/infection (according to investigator judgment) on the day of vaccination or febrile illness (temperature ≥ 37.1°C). A prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided.

• History of contra-indication to vaccination with pertussis containing vaccine, including:

  • Encephalopathy (e.g, coma, decreased level of consciousness, prolonged seizures) within 7 days of a previous dose of a pertussis containing vaccine that is not attributable to another identifiable cause
  • Progressive neurologic disorder, including infantile spasms, uncontrolled epilepsy, progressive encephalopathy
  • Axillary temperature >39.4°C within 48 hours not attributable to another identifiable cause
  • Collapse or shock-like state (hypotonic-hyporesponsive episode) within 48 hours.

• Prior personal history of Guillain-Barré syndrome.

• Identified as an Investigator or employee of the Investigator or study center with direct involvement in the proposed study, or identified as an immediate family member (i.e., parent, spouse, natural or adopted child) of the Investigator or employee with direct involvement in the proposed study.

• Subject is pregnant, or lactating, or of childbearing potential (to be considered of non-childbearing potential, a female must be pre-menarche or post-menopausal for at least 1 year, surgically sterile, or using an effective method of contraception or abstinence from at least 4 weeks prior to the vaccination and until at least 4 weeks after the vaccination.