Safety and Immunogenicity of a Single Dose of Intranasal Seasonal Trivalent Live-Attenuated Influenza Vaccine

Assessment of the Safety and Immunogenicity of a Single Dose of Intranasal Seasonal Trivalent Live-Attenuated Influenza Vaccine Among Children Aged 24 Through 59 Months in Bangladesh

In this Phase II randomized controlled clinical trial, generally healthy male and female children from 24 through 59 months of age will be enrolled in Kamalapur (Dhaka), Bangladesh. The study is expected to continue for at least 6 months following vaccination. The experimental intervention is Serum Institute of India Ltd's Trivalent, Seasonal Live Attenuated Influenza Vaccine (SIIL LAIV). The study vaccine has been formulated according to WHO recommendations for the 2011-2012 Northern Hemisphere influenza season. The SIIL LAIV is administered in a 0.5 ml intranasal dose (one spray of 0.25 ml per nostril) via a reusable sprayer device and a single-use nozzle that produces a fine mist that is primarily deposited in the nose and nasopharynx. The comparator vaccine will be an inactive placebo identical in appearance to the active vaccine.

The primary study hypothesis is that LAIV is safe and well tolerated by children aged 24 through 59 months in Bangladesh. A secondary hypothesis is that LAIV is immunogenic among children receiving study vaccine as compared to children receiving placebo.

Inclusion Criteria:

• Healthy male or female child at least 24 months of age and no older than 59 months of age at the time of study vaccination
• A child whose parent or guardian's primary residence, at the time of study vaccinations, is within the Kamalapur surveillance site catchment area and who intends to be present in the area for the duration of the trial
• A child whose parent or legal guardian is willing to provide written informed consent prior to the participant's study vaccination

Exclusion Criteria:

• Has any serious chronic disease including progressive neurologic disease, tuberculosis, Down's syndrome or other cytogenetic disorder, or known or suspected disease of the immune system
• Is receiving immunosuppressive agents including systemic corticosteroids during the two weeks prior to study vaccination
• Has a history of documented hypersensitivity to eggs or other components of the vaccine (including gelatin, sorbitol, lactalbumin and chicken protein), or with life-threatening reactions to previous influenza vaccinations
• Is receiving aspirin therapy or aspirin-containing therapy currently or two weeks before
• Lives in household with somebody currently participating in a respiratory vaccination or antiviral study
• Has current or past participation (within 2 months of trial enrollment visit) in any clinical trial involving a drug or biologic with activity against respiratory disease
• Has any condition determined by investigator as likely to interfere with evaluation of the vaccine or be a significant potential health risk to the child