TIV Infant/Toddler Response Evaluation - Follow-up for Influenza B Boost

Study Overview
=================
Brief Summary
-----------------
Each winter, viruses belonging to two kinds of influenza A (A/H1N1 & A/H3N2) and two kinds of influenza B (B/Yamagata & B/Victoria) can cause illness. The yearly influenza vaccine is designed to protect against both kinds of influenza A but only one or the other kind of influenza B. Current recommendations in Canada are that if an eligible child less than nine years of age has received two doses of influenza vaccine before, then that child only requires a single dose of influenza vaccine in subsequent years of immunization. In a previous study conducted in early 2010 we measured the antibody response to influenza B in children who had previously received two doses of a B/Yamagata kind of virus contained in the 2008-09 influenza vaccine and just one dose of the B/Victoria kind of virus contained in the 2009-10 recommended vaccine. The purpose of this follow-up study is to see if the protection (antibodies in the blood) provided against the influenza B/Victoria kind of virus that was in the 2009-10 vaccine can be improved with another (second) dose of the same B/Victoria kind of virus included in the 2010-11 vaccine. Since influenza B is an illness especially of children, understanding how to best protect children against both kinds of influenza B is important.

Official Title
-----------------
TITRE IIB Follow-Up: TIV Infant/Toddler Response Evaluation - Follow-up for Influenza B Boost

Conditions
-----------------
Influenza

Intervention / Treatment
-----------------
* Biological: 2010-11 trivalent inactivated influenza vaccine


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Child previously participated in the TITRE II study; Child is healthy (stable chronic conditions acceptable) as established by health assessment interview and verbal history-directed health examination; Child is available and can complete all relevant procedures during the study period; Parent or legal guardian is available and can be reached by phone during the study period; Parent/guardian provides written informed consent; And, parent/guardian is fluent in English/French. Exclusion Criteria: Child has already received the 2010-11 seasonal (TIV) influenza vaccine Child has received immune globulin or other blood products within the prior six weeks; Child has received injected or oral steroids within prior six weeks; Child is or will be enrolled in any other clinical trial of a drug, vaccine or medical device during the study period; Or, child has a recently acquired health condition which, in the opinion of the investigator, would interfere with the evaluation or pose a health risk to the child.

Ages Eligible for Study
-----------------
Minimum Age: 29 Months
Maximum Age: 51 Months

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| 2010-11 influenza vaccine recipients<br>Participants of an earlier clinical trial (TITRE II) to evaluate prime-boost response across B lineages in 2009-10 | Biological: 2010-11 trivalent inactivated influenza vaccine<br>* A single age-appropriate dose of 2010-11 trivalent inactivated influenza vaccine<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The seroprotection rate for B/Brisbane/60/2008(Victoria)-like and B/Florida/4/06(Yamagata)-like viruses | The seroprotection rate based on hemagglutination inhibition (HI) assay for B/Brisbane/60/2008(Victoria)-like and B/Florida/4/06(Yamagata)-like viruses following a single age-appropriate dose of 2010-11 TIV containing B/Brisbane/60/2008(Victoria)-like virus in young children originally primed with two doses of 2008-09 TIV containing B/Florida/4/2006(Yamagata) and who had received a single dose of the 2009-10 TIV containing B/Brisbane/60/2008(Victoria) virus | 4-6 weeks following a single dose of 2010-11 trivalent inactivated influenza vaccine (TIV) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Antibody response to other relevant TIV components | Other indicators of antibody response to each of the relevant TIV components will also be assessed | 4-6 weeks following a single dose of 2010-11 TIV | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
Influenza vaccines, Infant, Dose-Response relationship, immunologic, Prime-boost response