Hepatitis A Virus Infection
Conditions
Brief summary
This study will demonstrate the immunogenicity and evaluate the safety/tolerability of the vaccine in Chinese children between 12 and 23 months of age.
Interventions
BIOLOGICALHepatitis 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.
Sponsors
Merck Sharp & Dohme LLC
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
12 Months to 23 Months
Healthy volunteers
Yes
Inclusion criteria
* Healthy Chinese children 12 to 17 months old at receipt of the first study vaccination
Exclusion criteria
* Subject is Hepatitis A virus antibody positive at screening or has a history of Hepatitis A infection * Subject has a fever 72 hours prior to first injection * Subject has already been vaccinated for Hepatitis A * Subject is allergic to aluminum, formaldehyde, sodium borate, latex, or any component of the vaccine * Subject has received inactivated vaccines within 14 days of screening or live vaccines within 30 days of screening
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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. | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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 | 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. |
Participant flow
Pre-assignment details
114 subjects were enrolled for vaccination screening. Subject eligibility was reviewed according to the inclusion/exclusion criteria, and blood samples were collected for HAV (hepatitis A virus) antibody and ALT (alanine aminotransferase) testing. Finally 80 HAV-susceptible subjects with normal ALT were administered vaccines at the Day 1
Participants by arm
| Arm | Count |
|---|---|
| VAQTA™ Subjects be given a 25-U/0.5-ml intramuscular injection of VAQTA™ at the Day 1 and Month 6 visits respectively. | 80 |
| Total | 80 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 2 |
Baseline characteristics
| Characteristic | VAQTA™ |
|---|---|
| Age, Continuous | 14.7 Months STANDARD_DEVIATION 1.6 |
| Body Temperature | 35.56 Degrees Celsius STANDARD_DEVIATION 0.31 |
| Pulse | 80.05 Beats per minute (BPM) STANDARD_DEVIATION 5.04 |
| Sex: Female, Male Female | 37 Participants |
| Sex: Female, Male Male | 43 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | — / — |
| other Total, other adverse events | 56 / 80 |
| serious Total, serious adverse events | 0 / 80 |
Outcome results
Primary
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.
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.
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)
Population: Per-protocol population, defined as all HAV-susceptible subjects who completed the vaccination regimen within acceptable day ranges, had 2 valid serology results on Day 0 and Month 7, and met all inclusion/exclusion criteria.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| VAQTA™ | 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. | Seronegative at Month 7 | 2 Percentage of Participants |
| VAQTA™ | 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. | Seropositive at Month 7 | 68 Percentage of Participants |
95% CI: [89, 99]
Secondary
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
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.
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
Population: Safety population, defined as all subjects who were vaccinated at least one dose and had safety follow-up data
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| VAQTA™ | 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 | Serious adverse experiences | 0 participants |
| VAQTA™ | 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 | Systemic adverse experiences | 54 participants |
| VAQTA™ | 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 | Injection-site adverse experiences | 10 participants |