A Study of 2 Doses of VAQTA™ in Healthy Children 12 to 23 Months of Age (V251-069)
|Hepatitis A Virus Infection||Biological: Hepatitis A Vaccine, Purified Inactivated (VAQTA™)||Phase 3|
|Study Design:||Allocation: Non-Randomized
Intervention Model: Single Group Assignment
Masking: No masking
Primary Purpose: Prevention
|Official Title:||A Phase III Open-Label Study of Immunogenicity, Safety, and Tolerability of 2 Doses of VAQTA™ (Formalin, Inactivated, Alum-Adjuvanted Hepatitis A Vaccine) in Healthy Children 12 to 23 Months of Age|
- Hepatitis A Virus (HAV) Seroconversion Rate, i.e. the Percentage of Subjects Who Were Seronegative at Baseline and Developed Seropositive at Month 7 After Administration of a 2-dose Regime of Vaccines. [ Time Frame: Collect blood sample for HAV antibody testing at Day 0 prior to vaccination, and Month 7 (4 weeks after administration of a 2-dose regimen of vaccines at Month 6) ]
Seroconversion rate = (number of subjects with seronegative at baseline and developed seropositive at Month 7)/(number of subjects with seronegative at baseline regardless HAV serum status at Month 7). Measure serum HAV (hepatitis A virus) antibody at Day 0 prior to vaccination and at Month 7 after administration of a 2-dose regimen of vaccines.
HAV antibody titers were determined by Wantai ELISA kit for serum antibody response to HAV. Seropositive was defined as HAV antibody titer ≥ 50 mIU/mL. Seronegative was defined as HAV antibody titer < 50 mIU/mL.
- Serious Adverse Experiences and Systemic Adverse Experiences Occurring Within 14 Days After Each Vaccination, and Injection-site Complaints Occurring Day 1 Through Day 5 After Each Vaccination [ Time Frame: For serious adverse experiences and systemic adverse experiences: 14 days follow-up after each dose of vaccination; For injection-site adverse experiences: 5 days follow-up after each dose of vaccination ]All adverse experiences were collected from the time the consent form was signed through 14 days following the first vaccination(s) and from the time of the second vaccination through 14 days thereafter. The parent/legal guardian of each participant were requested to record injection-site adverse experiences and monitor the subject's temperature daily on the Vaccination Report Card for Day 1 thereafter for 4 additional calendar days, and record all systemic adverse experiences that occur during the 14-day period after each injection.
|Study Start Date:||March 2008|
|Study Completion Date:||October 2008|
|Primary Completion Date:||October 2008 (Final data collection date for primary outcome measure)|
Biological: Hepatitis A Vaccine, Purified Inactivated (VAQTA™)
Subjects will be given a 25-U/0.5 mL intramuscular injections of VAQTA™ at Day 1 and Month 6.
Other Name: VAQTA™
Please refer to this study by its ClinicalTrials.gov identifier: NCT00835380
|Study Director:||Medical Monitor||Merck Sharp & Dohme Corp.|