The purpose of this study is to evaluate how young children's bodies learn to fight against flu infection and to see how vaccines may help to fight against the flu. This is a Phase 4, single-center, randomized study of the immune responses of 40 children, ages 5-9, given one of two licensed influenza vaccines (either inactivated vaccine given in an arm muscle or live, attenuated vaccine inhaled through the nose). Study procedures will include up to 3 blood samples. Participants will complete a diary to document any side effects experienced following the vaccination. Participants will return to the clinic for a visit on Day 7-9 and again 4-6 weeks following vaccination. Participants that have not been previously vaccinated will receive a 2nd dose of vaccine. A follow up telephone call will occur 8-10 weeks following vaccination. Total study participation will be up to 75 days.
This is a Phase 4, single-center, randomized clinical trial of the immune responses of children given one of two licensed influenza vaccines (either inactivated vaccine given IM or live, attenuated vaccine given intranasally). This study will enroll 40 healthy children 5-9 years of age. Subjects will be randomized to receive either FluMist or Fluzone. FluMist is approved for children older than 5 years and Fluzone is also approved for a broader age indication starting at 6 months of age. Subjects who receive FluMist will have the vaccine administered intranasally by large particle aerosol, 0.25 mL per nostril. Subjects receiving Fluzone will receive 0.5 mL given intramuscularly into the non-dominant deltoid muscle. Children who have not previously been immunized against influenza will receive a second dose of vaccine 4 weeks after the first dose. Children who receive two doses of vaccine will remain on the study for 8-10 weeks. The primary objective of this study is to compare the effector B cell responses at Day7-9 and the CD4 and CD8 T-cell responses, memory B-cell and the serology responses at Day 28 post-immunization following administration of one of two different influenza vaccines. Researchers will evaluate any increases in the immune response (CD4, CD8, B cell and serology responses) Day 0 to Day 7-9 for T-cells and ASCs, and from Day 0-28 for memory B-cell and serology responses. NK-cell and homing studies will also be compared between the groups.