Trial to Compare the Safety, Tolerability, and Efficacy of Influenza Virus Vaccine, (CAIV-T) With Inactivated, Influenza Vaccine, Trivalent, Types A & B, in Adults Aged 60 Years and Older Against Culture-confirmed Influenza

To demonstrate that the efficacy over a defined surveillance period against culture-confirmed influenza-illness caused by community-acquired subtypes antigenically similar to those contained in the vaccine, in adults aged at least 60 years at enrollment, of a single intranasally (IN) -administered dose of a liquid formulation of influenza virus vaccine,(CAIV-T) is non inferior compared with that of a single dose of commercially available influenza vaccine inactivated (TIV) administered intramuscularly (IM) prior to the anticipated commencement of the influenza season.


Eligibility Criteria:
Inclusion Criteria:

* who are aged at least 60 years or older at the time of enrollment;
* who are determined by medical history, physical examination and clinical judgement to be eligible for this study;
* who have provided written informed consent after the nature of the study has been explained;
* who will be available for duration of the trial (from enrollment to November 30th, 2003);
* who can be reached by study staff for the post-vaccination and weekly surveillance contacts \[telephone, clinic or home visit\].

Exclusion Criteria:

* who are perceived to be unavailable or difficult to contact for evaluation or study visits during the study period;
* who are a resident of a nursing home or long-term care facility or other institution receiving skilled or semi-skilled nursing care (refer to Influenza study specific manual). An ambulatory subject who is a resident of a retirement home or village is eligible for the trial;
* with any signs of renal insufficiency requiring supportive therapy or progressive neurological disease. (Subjects with other 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).
* with evidence of dementia or other severe cognitive impairment based on Mini Mental State Examination (MMSE) scores (refer to Influenza study specific manual);
* with a known or suspected disease of the immune system or those receiving immunosuppressive therapy, including systemic corticosteroids; or cytotoxic agents;
* who received any blood products, including immunoglobulin, in the period from six months prior to vaccination through to the conclusion of the study;
* have an immunosuppressed or an immunocompromised individual living in the same household;
* with a documented history of hypersensitivity to egg or egg protein or any other component of the CAIV-T or TIV vaccine;
* who were administered any live virus vaccine within one month prior to vaccination or expected to receive another live virus vaccine within one month of vaccination in this study;
* for whom there is intent to administer any other investigational vaccine or agent from one month prior to enrollment through to the conclusion of the study;
* who received a dose of influenza treatment (commercial or investigational) one month prior to enrollment. The prophylactic use of influenza antivirals is not permitted.
* who receive any influenza vaccine in the 6 months prior to enrollment, or intend to receive a non-study influenza vaccine after enrollment;
* with any medical conditions that in the opinion of the investigator might interfere with interpretation of the study results; Note: A pregnant household member is not considered a contraindication to enrollment.