• Effectiveness [ Time Frame: pre-, post- and the influenza outbreak periods ] [ Designated as safety issue: No ]
  Age-specific rates for medically attended acute respiratory illness (MAARI) in the pre-, post- and the influenza outbreak periods will be calculated for the intervention and comparison communities. Overall effectiveness will be evaluated in the intervention communities. Overall effectiveness will compare age-specific MAARI rates during the influenza outbreak for SWHP members in the intervention and comparison communities, irrespective of influenza vaccination status.
  
  

• Effectiveness and safety [ Time Frame: pre-, post- and the influenza outbreak periods ] [ Designated as safety issue: Yes ]

  Age-specific rates for MAARI and P&I will be determined in seasonal (CAIV-T and IIV-T) and pandemic SWHP student vaccinees compared to age-eligible SWHP non-participants who had never received seasonal (CAIV-T or IIV-T) or pandemic influenza vaccine in the intervention communities (direct effectiveness) and comparison communities (total effectiveness).

  Serious adverse events (SAEs) and MAARI adverse events within 42 days post vaccination will be captured in seasonal (CAIV-T and IIV-T) and pandemic vaccinated study subjects.

  
  

In this renewal application (2008-2012), the study goal is to control epidemic influenza through active immunization of healthy school-aged children with the cold-adapted, trivalent, live, attenuated influenza vaccine (LAIV)and at-risk children with the inactivated influenza vaccine (IIV) through a school-based vaccination program. The hypothesis is that universal vaccination of healthy school-aged children is an alternative and effective strategy for the control of epidemic influenza, and will serve as a model for the control of pandemic influenza and biodefense. The specific aims of the study are: to control the spread of influenza to susceptible adults 35 years of age or older by vaccination of school-aged children 4-18 years of age; to control the spread of influenza to susceptible children and young adults less than 35 years of age by vaccination of school-aged children 4-18 years of age; to develop a school-based vaccination program for rapid and timely delivery of LAIV and IIV to children 4-18 years of age; to demonstrate in school-aged children the direct and total effectiveness of influenza vaccines to reduce the rates of medically attended acute respiratory illness (MAARI) in LAIV and IIV recipients during influenza epidemics; and to capture safety information on LAIV post-licensure. This is an open-label, up to four year community-based study. In each of the first three study years, school-aged children (4 through 18 years of age) who receive medical care at the Scott & White Clinics (SWCs), Temple-Belton area, Texas, will be asked to participate in this study. Study participants will receive LAIV or IIV according to their health status. Other children from Temple-Belton area who do not receive medical care at the SWC will be invited to participate in the study and may receive LAIV or IIV. A comparable population enrolled in the SWCs in Waco/McLennan County area and Bryan/College Station will serve as comparison groups. In the fourth and final year of the study, LAIV will not be provided through the study. However, influenza surveillance will continue and MAARI data will be collected to assess continued protective benefit of influenza vaccines. The final year will also be devoted to completion of data analysis and preparation of manuscripts. Children 4 years through 8 years who have not previously been vaccinated with an influenza vaccine will be offered a second dose 4 to 6 weeks after the first dose. The influenza vaccines will contain the three influenza virus strains chosen by the FDA. Each subject will receive by nasal spray a 0.2 ml dose (0.1 ml in each nostril) of the LAIV or 0.5 ml intramuscularly. The duration of each study year is approximately five to ten months, from the time of enrollment (August to January, at the discretion of the investigators) depending on vaccine availability and the timing of influenza activity, to the end of the influenza season (May).