The purpose of this clinical study was to evaluate immune responses measuring antibodies in serum and secretions and cellular immune responses generated by CAIV-T vaccine in healthy adults aged 18 years and older as a means to develop assays for application in investigating potential immunological correlates of protection and/or establishing assays to measure vaccine take.

Inclusion Criteria:

• Healthy adults aged 18 to 59 years or > 60 years.
• Female subjects of childbearing potential who had a negative urine pregnancy test result prior to study vaccination. Females who were surgically sterile or post-menopausal did not require pregnancy testing.
• Adults who were determined by medical history, physical examination and clinical judgment eligible for this study. Subjects with stable pre-existing disease, defined as disease not requiring change in therapy or hospitalization within 12 weeks before receipt of study vaccination, will be eligible.
• Subjects who provided written informed consent after the nature of the study was explained.
• Subjects who were available for the duration of the study (from enrollment to study completion).
• Subjects who could be reached by study staff for the post-vaccination contact [via telephone, clinic or home visit].

Exclusion Criteria:

• For subjects > 60 years of age only:
• Subjects who resided in a nursing home or long-term care facility or other institution receiving skilled or semi-skilled nursing care. An ambulatory subject who resided in a retirement home or village was eligible for participation.
• Subjects with evidence of dementia or other severe cognitive impairment based on Mini Mental State Examination (MMSE) scores. Note: Prior to study vaccination, all subjects >60 years of age must have completed a MMSE.

For all study subjects:

• Subjects who were perceived to be unavailable or difficult to contact for evaluation of study visits during the study period.
• Subjects with a known or suspected disease of the immune system or those receiving immunosuppressive therapy, including systemic corticosteroids; or cytotoxic agents.
• Subjects who resided in the same household as an immunosuppressed or immunocompromised individual.
• Subjects with a documented history of hypersensitivity to egg or egg protein or any other component of the study vaccine, placebo or TIV.
• Subjects who had a current wheezing episode that was considered a change from the subject's usual clinical state.