Hepatitis B
Conditions
Brief summary
The purpose of this study is to demonstrate the durability of protection against hepatitis B virus (HBV) infection approximately 8-9 years after vaccination with Vaxelis®. This is an estimation study, and no formal hypothesis testing was performed.
Interventions
BIOLOGICALHBVAXPRO™
Single 0.5 mL intramuscular dose
Sponsors
Merck Sharp & Dohme LLC
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
8 Years to 10 Years
Healthy volunteers
Yes
Inclusion criteria
* Is healthy (based on a review of medical history and targeted physical examination) based on the clinical judgment of the investigator. * Has participated in Protocol V419-007 and received a 3 + 1 Vaxelis® schedule or participated in Protocol V419-008 and received a 2 + 1 Vaxelis® schedule. * The participant (or legally acceptable representative if applicable) provides written informed consent/assent for the study.
Exclusion criteria
* Has a history of diagnosis (clinical, serological, or microbiological) of HBV infection. * Has a known or suspected impairment of immunological function (e.g., human immunodeficiency virus (HIV), splenectomy). * Has a known hypersensitivity to any component of the study vaccine. * Has a known or suspected blood dyscrasias, leukemia, lymphomas of any type or other malignant neoplasms affecting the haematopoietic and lymphatic system. * Has a bleeding disorder contraindicating intramuscular vaccinations. * Has received any hepatitis B vaccine after participation in Protocol V419-007 or V419-008. * Is or has an immediate family member (e.g., spouse, parent/legal guardian, sibling, or child) who is investigational site or Sponsor staff directly involved with this study.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™ | Day 30 | Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen | Day 1 and Day 30 | Participant serum samples will be assessed with an ECi assay for anti-HBs geometric mean concentrations (GMCs) pre-challenge on Day 1 and 30 days post-challenge with HBVAXPRO™ in mIU/mL. |
Countries
Finland
Participant flow
Pre-assignment details
Approximately 200 planned to be enrolled and 207 were enrolled.
Participants by arm
| Arm | Count |
|---|---|
| HBVAXPRO™ Healthy children vaccinated approximately 8-9 years previously with a 2- or 3-dose infant series and toddler dose of Vaxelis® who received a single dose of Hepatitis B vaccine challenge (HBVAXPRO™). | 207 |
| Total | 207 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Withdrawal by Subject | 2 |
Baseline characteristics
| Characteristic | HBVAXPRO™ |
|---|---|
| Age, Continuous | 8.4 years STANDARD_DEVIATION 0.5 |
| Ethnicity (NIH/OMB) Hispanic or Latino | 2 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 205 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants |
| Race (NIH/OMB) More than one race | 2 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants |
| Race (NIH/OMB) White | 205 Participants |
| Region of Enrollment Finland | 207 Participants |
| Sex: Female, Male Female | 97 Participants |
| Sex: Female, Male Male | 110 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 207 |
| other Total, other adverse events | 0 / 205 |
| serious Total, serious adverse events | 0 / 205 |
Outcome results
Primary
Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™
Participant serum samples were collected for analysis with an enhanced chemiluminescence (ECi) assay to determine the concentration of antibodies to hepatitis B surface antigen (HBsAg). Response rate was the percentage of participants with a protective hepatitis B surface antibody (anti-HBs) level of ≥ 10 mIU/mL at Day 30 post-challenge.
Time frame: Day 30
Population: The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.
| Arm | Measure | Value (NUMBER) | Dispersion |
|---|---|---|---|
| HBVAXPRO™ | Percentage of Participants With a Protective Hepatitis B Surface Antibody Level of ≥10 Milli International Units/mL (mIU/mL) at 30 Days Post-Challenge With HBVAXPRO™ | 99.5 Percentage of Participants | 95% Confidence Interval 97.3 |
Secondary
Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen
Participant serum samples will be assessed with an ECi assay for anti-HBs geometric mean concentrations (GMCs) pre-challenge on Day 1 and 30 days post-challenge with HBVAXPRO™ in mIU/mL.
Time frame: Day 1 and Day 30
Population: The analysis population consisted of all enrolled participants without deviations from the protocol (i.e., did not receive study vaccine, use of prohibited medicine/vaccine, or blood sample collected outside of analysis window) that may substantially affect the results of the immunogenicity endpoint.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| HBVAXPRO™ | Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen | Day 30 Post-challenge | 685.84 mIU/mL |
| HBVAXPRO™ | Geometric Mean Concentration of Antibodies to Hepatitis B Surface Antigen | Day 1 Pre-challenge | 9.63 mIU/mL |