Randomized Study of Immune Response to Licensed Influenza Vaccines in Children and Adolescents

Prospective Randomized Study of Immune Response to Licensed Influenza Vaccines in Children and Adolescents

The purpose of this study is to assess the serologic and cell-mediated immune response to licensed live attenuated influenza vaccine (LAIV) and inactivated influenza vaccine (IIV) in children 5-17 years old. The effects of prior infection and or prior season vaccination will be examined. Children will be followed during the influenza season to identify laboratory-confirmed influenza (i.e. vaccine failure).

All children will have baseline blood samples drawn and will then be vaccinated with licensed and approved influenza vaccines. Following the recommendation from the Advisory Committee on Immunization Practices, children 5-8 years old will preferentially receive live attenuated influenza vaccine (LAIV). Children aged 9-17 will be randomized to receive either LAIV or inactivated influenza vaccine (IIV). Children with a medical contraindication to any licensed influenza vaccine will be excluded from the study.

The children will have their blood drawn between 2 and 4 times total over the course of two months in order to test their immune response to the vaccine. Between approximately December and April, study participants will be contacted weekly to monitor for any new respiratory illnesses with cough, and if present, nasal and throat swabs will be collected to test for influenza.

Inclusion Criteria:

• Aged 5-17 years for the duration of the study period (Sept 1, 2014-Apr 1, 2015)
• Enrolled in either the immune response study or the vaccine effectiveness study conducted at the site in the 2013-14 influenza season
• If enrolled in the vaccine effectiveness study the previous season must have either been vaccinated and infected with influenza or unvaccinated and uninfected with influenza

Exclusion Criteria:

• Children with contraindications to either the quadrivalent live attenuated influenza vaccine or to the trivalent inactivated influenza vaccine will be excluded.
• Anyone unwilling or unable to complete all required study activities including informed consent
• Subjects who already received the influenza vaccine for the 2014-15 season