Trial to Compare the Safety,Tolerability and Efficacy of Influenza Virus Vaccine, (CAIV-T) With Influenza Virus Vaccine, Trivalent, Inactivated (TIV) in Children

Inclusion Criteria: who are aged at least 6 months and less than 72 months of age at the time of enrolment; who have experienced two or more practitioner attended RTIs* in the past 12 months (since birth if less than 12 months old); * RTIs are defined as upper RTIs including (but not limited to) common cold, acute otitis media and lower RTIs including (but not limited to) bronchiolitis, bronchitis and pneumonia. whose parent(s)/legal guardian(s) have provided written informed consent after the nature of the study has been explained; who, along with their parent(s)/legal guardian(s), will be available for duration of the trial; whose parent(s)/legal guardian(s), can be reached by study staff for the post-vaccination contacts [telephone, clinic or home visit]. Exclusion Criteria: whose parent(s)/legal guardian(s) are perceived to be unavailable or difficult to contact for evaluation or study visits during the study period; with any serious chronic disease (e.g., with signs of cardiac or renal failure or severe malnutrition), including progressive neurological disease; with Down's syndrome or other known cytogenetic disorders; with a known or suspected disease of the immune system or those receiving immunosuppressive therapy, including systemic corticosteroids of a dose equivalent to (i) 2mg/kg/day or greater of Prednisolone or (ii) equivalent to a total of 20 mg/day or greater for children who weigh more than 10kg, for more than 14 days duration until 2 weeks after corticosteroids have been discontinued 27; who received any blood products, including immunoglobulin, in the period from six months prior to vaccination through to the conclusion of the study; for whom there is intent to administer any other investigational vaccine or agent from one month prior to enrolment through to the conclusion of the study; who have an immunosuppressed or an immunocompromised individual living in the same household; who, at any time prior to entry into this study, received a dose of any influenza vaccine (commercial or investigational) or is anticipated to receive a non-study influenza vaccine after enrollment; with a documented history of hypersensitivity to egg or egg protein or any other component of CAIV-T or TIV; who received aspirin (acetylsalicylic acid) or aspirin-containing products in the two weeks prior to enrolment or for which use is anticipated during the study; with any medical conditions that in the opinion of the investigator might interfere with interpretation of the study results; Note: Pregnancy in any person who has regular contact with the subject is not a contraindication to the enrolment or ongoing participation of the subject in the study.