Genetic and Environmental Factors in the Response to Influenza Vaccination
Condition: Influenza; Healthy
MeSH terms: Influenza, Human
Study type: Interventional
Phase: Phase 1

Summary: 
      The purpose of the study is to investigate and compare the immune responses to influenza
      vaccination in monozygotic (identical) and dizygotic (fraternal) twins to determine the roles
      of genetics and environment in the response to flu vaccination.
    

Detailed description: 
      This is a phase 1 study of 120 healthy 12-49 year old adolescents and adult volunteers who
      are given licensed seasonal influenza vaccine. There are no exclusions for gender, ethnicity
      or race. The volunteers will be enrolled into one of 3 groups:

      Group A: Up to 40 healthy monozygotic (MZ) twin volunteers, 12-49 years old, will be given
      inactivated influenza vaccine quadrivalent (IIV4). Each volunteer will complete a total of 3
      visits: Day 0 (pre-immunization), Day 6-8 and Day 28+ 7 post-immunization. All visits will
      consist of drawing blood for study assays and monitoring for serious adverse events (SAEs).

      Group B: Up to 40 healthy dizygotic (DZ) twin volunteers, 12-49 years old, will be given
      inactivated influenza vaccine quadrivalent (IIV4). Each volunteer will complete a total of 3
      visits: Day 0 (pre-immunization), Day 6-8 and Day 28+7 post-immunization. All visits will
      consist of drawing blood for study assays and monitoring for serious adverse events (SAEs).

      Group C: Up to 40 healthy monozygotic (MZ) twin volunteers, 12-49 years old, will be
      randomized within the twin pair to receive either inactivated influenza vaccine quadrivalent
      (IIV4) or live, attenuated influenza vaccine quadrivalent (LAIV4). Each volunteer will
      complete a total of 3 visits: Day 0 (pre-immunization), Day 6-8 and Day 28+7
      post-immunization. All visits will consist of drawing blood for study assays and monitoring
      for serious adverse events (SAEs). This group was terminated in 2016 due to ACIP
      recommendations against the use of LAIV but was reopened in 2018 with the availability of
      LAIV4.

      Each twin is counted as a single participant. All reporting numbers reflect the number of
      participants, not the number of twin pairs.
    

Intervention name(s): FluMist® Quadrivalent; Fluzone® Quadrivalent vaccine
Intervention type(s): Biological; Biological
Intervention description(s): LAIV4 vaccine dosage is 0.2 mL. Vaccine will be administered as an intranasal spray. Each sprayer contains a single dose of FluMist® Quadrivalent; approximately one-half of the contents should be administered into each nostril. 0.1 mL (i.e., half of the dose from a single FluMist sprayer) is administered into each nostril while the recipient is in an upright position. Insert the tip of the sprayer just inside the nose and rapidly depress the plunger until the dose-divider clip stops the plunger. The dose divider clip is removed from the sprayer to administer the second half of the dose (0.1 mL) into the other nostril.; IIV4 vaccine will be administered as a 0.5 mL dose, with a sterile, disposable syringe and needle by IM injection into the deltoid muscle.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Inactivated influenza vaccine quadrivalent; Live, attenuated influenza vaccine quadrivalent; Monozygotic twins; Dizygotic twins; Adults; Adolescents