This is a sequential phase I and II, controlled, double-blinded study to determine whether immune responses suggesting protection against influenza can safely be induced in young children by two reduced doses one month apart of 0.1 mL of a trivalent inactivated influenza vaccine (INF) administered by the intradermal (ID) route with an investigational ID spacer on a United States (U.S.)-licensed needle-free jet injector (JI), compared to two standard intramuscular (IM) 0.25 mL doses by needle-syringe (N-S) in this age group. The locale is a developing country where financial restraints for the use of full-dose influenza vaccine would limit protection from an influenza pandemic threat, where N-Ss pose dangers and drawbacks in clinical use, and where Mantoux-type N-S ID injections are difficult to administer during mass campaigns.
Randomized, observer-blinded, clinical pilot (phase I) trial of safety, followed by a clinical (phase II) trial of safety and non-inferiority of immune response to the standard route and dose for the merged subjects from both phases. Phase I - Influenza-vaccine naïve children (n = 48) aged \>= 6 to \< 24 months will be randomized in a 1:1:1 ratio to the following three study arms, each to receive two doses on days 0 and 28 of trivalent inactivated influenza (INF) vaccine (Vaxigrip®, Sanofi Pasteur, Lyon, France) into the left thigh (\< 12 months) or left deltoid (≥ 12 months): * Group "ID-JI-0.1" (n = 16) - reduced 0.1 mL INF doses administered intradermally (ID) by needle-free jet injector (JI) (Biojector® 2000 subcutaneous syringe no. 2 \[green color code\], with 2 cm investigational spacer, Bioject Medical Technologies, Inc., Portland, OR, USA) * Group "IM-NS-0.1" (n = 16) - reduced 0.1 mL INF doses administered intramuscularly (IM) needle-syringe (NS) (via 22-25 gauge needle, minimum 25 mm/1-inch length) * Group "IM-NS-0.25" (controls) (n = 16) - full 0.25 mL INF doses administered intramuscularly (IM) by needle-syringe (NS) (22-25 gauge needle, minimum 25 mm/1-inch length) Phase II - Upon assessment of the safety profile from phase I by the unblinded Data Safety Monitoring Board (DSMB), with its approval an additional 402 children will be recruited and randomized (134 per group) as in phase I above. Total subjects in phase I and II = 450 (150 in each of three study arms). Adverse Event Diaries: Parents will be trained to complete a diary form to observe, measure, and record solicited local reactions for the injection site and systemic signs and symptoms for the child for days 0 through 7 after vaccination, plus unsolicited symptoms, illness, and medications for days 0 through 28. Followup: Return clinic visits will be scheduled on days 2, 7, and 28 after INF dose 1, at which times the diary card data will be recorded by staff and the card collected on day 28. Upon receiving dose 2 of vaccine, patients will be scheduled again to return to the study center 2, 7, and 28 days afterwards. The same procedures as for dose 1 regarding diary cards, telephone followup, and home visits will apply after dose 2. Upon returning to clinic on day 28 after dose 2 (day 56 after dose 1), the child will receive an unblinded, "insurance", full-volume, 0.25 mL dose (#3) of influenza vaccine by NS IM, unless he or she is in the full-dose IM control group IM-NS-0.25, in which case a mock injection will be administered instead of a 3rd full dose beyond the usual 2-dose series. All participants will return 6 months after this third injection for a fourth "bonus" dose of influenza vaccine to ensure protection for the following season. Serum Collection: Blood specimens to measure serologic responses will be collected three times, just prior to vaccination on day 0 (INF dose 1), on day 28 (INF dose 2), and on day 56 (INF "insurance" dose 3). Ethical oversight additional to CDC IRB G by (1) World Health Organization Research Ethics Review Committee, (2) Consejo Nacional de Bioética en Salud, and (3) Fundación Dominicana de Infectología Comité de Etica/Investigaciones.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
QUADRUPLE
Enrollment
450
See full description elsewhere in this record.
See elsewhere in this record for full description.
Hospital Infantíl Dr. Robert Reid Cabral
Santo Domingo, Nacional, Dominican Republic
Rates of seroconversion (SC) on HI assay 1 month after dose 2. SC defined as titer >= 40 among initial-seronegatives (titer < 8 on day 0); OR, a followup titer which rises >= 4-fold.
seroconversion and safety assessed through occurrence of local and systemic reactions
Time frame: One month after each of doses 1 and 2.
Rates of local and systemic reactions
assessment of these reactions by study investigators
Time frame: Up to 42 days for prompted symptoms after investigational doses 1 and 2. Up to 6 months for unsolicited ones.
Seroprotection (SP) on HI assay, defined as >= 40 regardless of baseline
assays were performed at CDC
Time frame: One month after each of doses 1 and 2.
Geometric mean titers (GMT) on HI
assays were performed at CDC
Time frame: One month after each of doses 1 and 2.
Geometric mean increase (GMI) on HI
assays were performed at CDC
Time frame: One month after each of doses 1 and 2.
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