To compare the seroprotection rates and booster responses to Canadian-manufactured Tetanus and Diphtheria Toxoids Adsorbed vaccine to the seroprotection rates and booster responses to the US-manufactured Tetanus and Diphtheria Toxoids Adsorbed vaccine when administered to subjects ≥ 60 years of age.

To compare the post-vaccination geometric mean titers of antibody (GMTs) to Canadian manufactured Tetanus and Diphtheria Toxoids Adsorbed vaccine to the post-vaccination GMTs to the US manufactured Tetanus and Diphtheria Toxoids Adsorbed vaccine when administered to subjects ≥ 60 years of age.

This is a multi-center, partially open-label, partially randomized double blind trial for immunogenicity and safety in the United States. Participants will be enrolled to one of three treatment groups:

• Subjects ages 11-59 years will receive Canadian manufactured Td vaccine on Day 0
• Subjects 60 years or older will be randomized to receive either US manufactured Td on Day 0, or,
• Subjects 60 years or older randomized to receive Canadian manufactured Td on Day 0

The trial is designed to assess the safety of Canadian Manufactured Tetanus and Diphtheria Toxoids Adsorbed vaccine in all trial participants 11 to 59 years of age and to describe the immune responses in subsets of adolescents (11-14, and 15-18 years of age) and in a subset of adults 19-59 years of age. The trial will also compare the immune responses and safety in subjects ≥ 60 years of age receiving Canadian Manufactured Tetanus and Diphtheria Toxoids Adsorbed vaccine to an equal number of subjects ≥ 60 years of age receiving US Manufactured Tetanus and Diphtheria Toxoids Adsorbed vaccine.

Inclusion Criteria:

• Participant is healthy as per medical history reported by subject.
• Participant is at least 11 years of age at the time of vaccination.
• Participant has a signed Institutional Review Board (IRB)-approved informed assent/consent form. For subjects 11 to 17 years of age, a written informed consent must be obtained from parent(s) or legal guardian(s) and a written informed assent must be obtained from the subject
• Participant provides history or documentation of primary or booster immunization with Diphtheria and Tetanus.
• Female participants of childbearing potential must have a negative urine pregnancy test at the time of enrollment.

Exclusion Criteria:

• Serious and uncontrolled chronic disease (i.e., cardiac, pulmonary, renal, neurologic, metabolic, rheumatologic, etc.).
• Known or suspected impairment of immunologic function.
• Acute medical illness with or without fever within the last 72 hours or an oral temperature ≥ 100.4°F (≥ 38°C) at the time of enrollment.
• Administration of immune globulin or other blood products within the last three months; administration of corticosteroids (injected or oral) or other immunomodulatory therapy within six weeks of the study vaccine. However, individuals on a tapering dose schedule of oral steroids may be included in the trial, as long as steroids were discontinued more than two weeks prior to enrollment.
• Received any vaccine, other than influenza vaccine, in the 28-day period prior to enrollment or scheduled to receive any vaccination, other than influenza prior to Visit 2 blood draw. For influenza vaccine only, exclude if received in the 14 day period prior to enrollment or scheduled to receive in the 14 day period after Visit 1.
• Suspected or known hypersensitivity to Td components, thimerosal (for subjects > 60 years of age) or latex rubber.
• Unable to attend scheduled visits or unable to comply with the study procedures.
• Enrolled in another clinical trial.
• Any condition that would pose a health risk to the participant or interfere with the evaluation of the vaccine in the opinion of the investigator.
• A positive urine pregnancy test at the time of enrollment for all females of childbearing potential.
• Female of childbearing potential who does not agree either to remain abstinent or to use effective birth control during the period of the trial.
• Breast feeding during the period of the trial.
• A history of Guillain- Barré syndrome within 6 weeks after a previous dose of a tetanus toxoid-containing vaccine.
• Receipt of a tetanus or diphtheria vaccination within the 5 years prior to enrollment.
• A previous history of diphtheria disease within the last 25 years or tetanus disease
• History of Arthus-type hypersensitivity reaction or a temperature >103° F following a prior dose of tetanus toxoid, unless 10 years have elapsed since the previous dose.