FLU-VACS Comparative Study in Adults
Condition: Influenza
MeSH terms: Influenza, Human
Study type: Interventional
Phase: Phase 4

Summary: 
      The purpose of this study is to compare 2 licensed flu vaccines to each other and to placebo
      (inactive substance). The study will be conducted among healthy adult participants aged 18-49
      years and is expected to last 3 years. During year 1, participants will be assigned to
      receive 1 of the 2 licensed flu vaccines or placebo, given as either nasal spray
      (live-attenuated vaccine or placebo) or injection (inactivated vaccine or placebo).
      Participants will receive the same assigned vaccine or placebo during year 2. During year 3,
      participants will be followed, but will not receive flu vaccine. Each year blood samples will
      be collected before and 1 month after each vaccination and at the end of each flu season in
      order to measure how the body responds to the vaccine and how well participants were
      protected from the flu. During the flu season, participants with flu-like illness will
      provide information on symptoms and provide a throat swab to test for virus identification.
    

Detailed description: 
      Influenza occurs on an annual basis, producing significant mortality in most years, mainly in
      those with underlying conditions and those at extremes of age. This study is a
      placebo-controlled trial to examine efficacies of the live attenuated and inactivated
      influenza vaccines, and immune correlates of protection; the study will take place in
      Michigan over a three year period, and will target adults aged 18-49 years. Both vaccine
      preparations are licensed for this age group. In the first year, participants will be
      randomly assigned to receive one of the two licensed vaccines or placebo. In the second year,
      participant receipt of vaccine (updated according to national recommendations) or placebo
      will continue as assigned in the first year for returning participants, and new enrollees
      will be randomly assigned to intervention. In the third year, when duration of immunity will
      be evaluated, no interventions will be given. In all study years, blood specimens for
      serologic studies and specimens for virus identification will be collected and a number of
      laboratory studies will be performed so that it will be possible to achieve the study's
      objectives. The primary annual study outcome for efficacy is the proportion of subjects with
      laboratory-confirmed symptomatic influenza A or B illness, defined as influenza virus
      isolated in tissue culture from a throat swab obtained from a participant during an episode
      of illness meeting the influenza case definition that is confirmed as influenza by
      fluorescent antibody or polymerase chain reaction (PCR) techniques; or serologic confirmation
      of influenza infection in a participant with an episode of illness meeting the influenza case
      definition, specifically a 4-fold rise in hemagglutinin inhibition assay (HAI) antibody titer
      to a circulating influenza strain between post-vaccination (pre-season) and post-season
      paired sera. The influenza case definition is illness with at least one respiratory symptom
      (cough or nasal congestion) and at least one constitutional symptom (fever or feverishness,
      chills or body aches). Subjects will be evaluated for serious adverse events throughout each
      annual study period. Annually, the proportion of participants with local reactions during the
      first seven days or any adverse reactions during the first thirty days after vaccine receipt
      will be compared with recipients of placebo.
    

Intervention name(s): Cold-adapted live attenuated influenza virus vaccine, trivalent; Placebo; Trivalent inactivated influenza vaccine; Trivalent inactivated influenza vaccine; Placebo
Intervention type(s): Biological; Other; Biological; Biological; Other
Intervention description(s): Live-attenuated influenza vaccine; single annual dose administered as an intranasal spray.; Physiological saline administered as an intramuscular injection.; Inactivated influenza vaccine; single annual dose administered as an intramuscular injection..; Inactivated influenza vaccine; single annual dose administered as an intramuscular injection.; Normal allantoic fluid administered annually as an internasal spray.
Intervention MeSH terms: Vaccines
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Prevention
Keywords: FLU-VACS, influenza, vaccine