This randomized, controlled, double-blinded, dose-ranging, Phase I-II study in 600 healthy adults, 18 to 49 years old, is designed to investigate the safety, reactogenicity, and dose-related immunogenicity of an investigational inactivated influenza A/H5N1 virus vaccine when given alone or combined with aluminum hydroxide. A secondary goal is to guide selection of vaccine dosage levels for expanded Phase II trials based on reactogenicity and immunogenicity profiles. This dose optimization will be applied to both younger and older subject populations in subsequent studies. Subjects who meet the entry criteria for the study will be enrolled at one of 4 study sites and will be randomized into one of 8 groups to receive 2 doses of influenza A/H5N1 vaccine containing 3.75, 7.5, 15, or 45 mcg of HA with or without aluminum hydroxide adjuvant by intramuscular injection. Participants may be involved in study related procedures for up to 8 months.
This randomized, controlled, double-blinded, dose-ranging, Phase I/II study in healthy adults, 18 to 49 years old, is designed to investigate the safety, reactogenicity, and dose-related immunogenicity of an investigational inactivated influenza A/H5N1 virus vaccine when given alone or combined with aluminum hydroxide. The primary objectives are to: determine the dose-related safety of subvirion-inactivated H5N1 vaccine adjuvanted with aluminum hydroxide in healthy adults; determine the potential for aluminum hydroxide to enhance the immune response to subvirion-inactivated H5N1 vaccine in healthy adults approximately 1 month following receipt of 2 doses of vaccine; and provide information for the selection of the best dosage level for further studies. The secondary objective is to evaluate dose-related immunogenicity and the percent of subjects responding approximately 1 and 7 months after the first vaccination. This dose optimization will be applied to both younger and older subject populations in subsequent studies. Subjects who meet the entry criteria for the study will be randomized into 8 groups to receive 2 doses of influenza A/H5N1 vaccine containing 3.75, 7.5, 15, or 45 mcg of hemagglutinin (HA) with or without aluminum hydroxide adjuvant by intramuscular (IM) injection (N=60 or 120/vaccine dose group). The first vaccination will occur on Day 0. Symptoms and signs will be assessed in the clinic for at least 15 minutes after inoculation, and the subjects will maintain a memory aid to record oral temperature and systemic and local adverse events (AEs) for 7 days after each immunization. Subjects will be encouraged to take their temperature around the same time each day. All subjects will return to the clinic 2 days and 8 days after each vaccination for assessment of adverse events (AEs) and concomitant medications and targeted physical examination (if indicated). Memory aids will be reviewed at each visit. Approximately Day 28 after the first vaccination, subjects will return to the clinic for blood sample collection and safety follow-up, followed by a second vaccination. Approximately 56 days after first immunization (or about 28 days after the second vaccination), subjects will return to the clinic for immunogenicity blood sample collection, AE and concomitant medication assessment, and targeted physical examination (if indicated). At approximately Day 208 (7 months after the first vaccination), subjects will return to the clinic for a final immunogenicity blood sample collection and for follow-up (which includes a targeted physical examination \[if indicated\]). Blood samples collected prior to each vaccination and on Days 56 and 208 after the first vaccination will be tested in a central laboratory for the levels of neutralizing and HAI antibodies. The primary outcome measures will be the frequencies and severities of AEs in each group and the proportions of subjects who achieve a serum neutralizing antibody titer of greater than or equal to 1:40 against the influenza A/H5N1 virus on Day 56. Serum HAI and neutralizing antibody responses (including frequencies of 4 fold or greater rise in titers; geometric mean titers; and proportions of subjects achieving putative protective titers of neutralizing antibody 1 month after each dose of vaccine and 7 months after first dose) also will be assessed. Although the correlate of protection for infections caused by influenza A/H5N1 viruses in humans is unknown, a serum neutralizing antibody titer of greater than or equal to 1:40 may be considered protective, based on limited data regarding the levels of serum neutralizing antibody present in serum samples collected from humans who survived infections caused by influenza A/H5N1 viruses. This study is linked to DMID protocol 07-0022.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
DOUBLE
Enrollment
600
Aluminum hydroxide adjuvant at 1200 mcg/mL.
Inactivated monovalent subvirion influenza H5N1 vaccine produced with and without Aluminum hydroxide adjuvant. All formulations of the H5N1 vaccine are supplied in a unit dose (0.5 mL) vial as a sterile solution for intramuscular injection. Vaccine with adjuvant is a turbid liquid whitish-grey in color. Vaccine without adjuvant is essentially clear and slightly opalescent in color.
University of Maryland Baltimore
Baltimore, Maryland, United States
University of Rochester
Rochester, New York, United States
Duke University Medical Center
Durham, North Carolina, United States
Baylor College of Medicine
Houston, Texas, United States
Adverse event (AE) or serious adverse event (SAE) information (solicited in the clinic and via memory aids, concomitant medications, and periodic targeted physical assessments).
Time frame: Adverse events will be collected through 28 days following the second dose of vaccine (approximately Day 56). Serious adverse events will be collected throughout the study through Day 208.
Proportion of subjects in each group achieving a serum neutralizing antibody titer of greater than or equal to 1:40 against the influenza A/H5N1 virus.
Time frame: 28 days following second dose of vaccine.
Proportion of subjects in each dose group achieving a serum Hemagglutination Inhibition (HAI) antibody titer of greater than or equal to 1:40 against the influenza A/H5N1 virus.
Time frame: 28 days following second dose of vaccine.
Geometric mean titer (GMT) and frequency of 4-fold or greater increases in neutralizing antibody titers in each group.
Time frame: 28 days following second dose of vaccine.
Geometric mean titer (GMT) and frequency of 4-fold or greater increases in serum HAI antibody titers in each group.
Time frame: 28 days after receipt of the second dose of vaccine.
1 month after receipt of each dose, and 7 months after receipt of the first dose of vaccine.
Time frame: 1 month after receipt of each dose, and 7 months after receipt of the first dose of vaccine.
Geometric mean titer (GMT) and the frequency of 4-fold or greater increases in serum HAI antibody titers.
Time frame: 1 month after receipt of each dose, and 7 months after receipt of the first dose of vaccine.
Development of serum antibody responses against antigenically drifted variants of H5N1 influenza virus.
Time frame: Blood samples for serum assays will be collected at day 0 and at days 28, 56, and 208 after the first immunization.
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