Encephalitis, Japanese Encephalitis
Conditions
Keywords
Encephalitis, Japanese Encephalitis, Japanese Encephalitis Chimeric Virus Vaccine, Toddlers
Brief summary
This is a long-term follow-up of the persistence of immune response in participants who previously received a single dose of JE-CV at age 12 to 18 months in Study JEC02 (NCT00735644) . No vaccination was administered during the present long-term follow-up study. Primary Objective: * To describe the yearly persistence of humoral immune response to Japanese encephalitis after a single dose of JE-CV
Detailed description
Persistence of immune response will be determined in participants who previously received a single dose of JE-CV at age 12 to 18 months in Study JEC02 (NCT00735644). No vaccination will be given in this study.
Interventions
OTHERBlood sample
Blood sample for immunogenicity assessment
BIOLOGICALJE-CV administered in Study JEC02
Participants received a single dose of JE-CV at 12 to 18 months of age in Study JEC02. No vaccination was administered in Study JEC05
Sponsors
Sanofi Pasteur, a Sanofi Company
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
2 Years to 3 Years
Healthy volunteers
Yes
Inclusion criteria
: * Provision of Informed Consent Form signed by at least one parent or other legally acceptable representative, and by at least one independent witness if required by local regulations. * Participant who was vaccinated with JE-CV in JEC02 trial and had a pre-vaccination blood sample at baseline in JEC02 trial. * Participant and parent/legally acceptable representative able to attend all scheduled visits and comply with all trial procedures.
Exclusion criteria
: * Receipt of any JE vaccine other than JE-CV during JEC02 trial and during the period up to inclusion in JEC05 trial. * Planned participation in another clinical trial up to the first year of the follow-up in the present trial.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Day 0 (pre-vaccination) from study JEC02, Day 28 post-vaccination from study JEC02, and at Years 1, 2, 3, 4, and 5 post-vaccination | Seroprotection was defined as the proportion of participants with Japanese encephalitis virus neutralizing antibody titers ≥10 1/dil as measured by a JE 50% plaque reduction neutralization test (PRNT50). |
| Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Day 0 (pre-vaccination) from JEC02, Day 28 post-vaccination from JEC02, and at Years 1, 2, 3, 4, and 5 post-vaccination | Geometric mean titers of Japanese encephalitis virus antibodies were assessed using the PRNT50 test. |
Countries
Philippines, Thailand
Participant flow
Recruitment details
Study participants were enrolled at 3 sites in Thailand and 2 sites in the Philippines.
Pre-assignment details
A total of 596 participants received a single dose of JE-CV in JEC02 and came to Visit 1 (Year 1) in JEC05; 585 participants were included in the Per Protocol Analysis set.
Participants by arm
| Arm | Count |
|---|---|
| Study Group Participants received a single dose of JE-CV in Study JEC02 | 585 |
| Total | 585 |
Withdrawals & dropouts
| Period | Reason | FG000 |
|---|---|---|
| Overall Study | Lost to Follow-up | 15 |
| Overall Study | Protocol Violation | 84 |
| Overall Study | Withdrawal by Subject | 18 |
Baseline characteristics
| Characteristic | Study Group |
|---|---|
| Age, Categorical <=18 years | 585 Participants |
| Age, Categorical >=65 years | 0 Participants |
| Age, Categorical Between 18 and 65 years | 0 Participants |
| Age, Continuous | 26.2 months STANDARD_DEVIATION 1.86 |
| Region of Enrollment Philippines | 229 participants |
| Region of Enrollment Thailand | 356 participants |
| Sex: Female, Male Female | 272 Participants |
| Sex: Female, Male Male | 313 Participants |
Adverse events
| Event type | EG000 affected / at risk |
|---|---|
| deaths Total, all-cause mortality | 0 / 591 |
| other Total, other adverse events | 0 / 591 |
| serious Total, serious adverse events | 0 / 591 |
Outcome results
Primary
Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV
Seroprotection was defined as the proportion of participants with Japanese encephalitis virus neutralizing antibody titers ≥10 1/dil as measured by a JE 50% plaque reduction neutralization test (PRNT50).
Time frame: Day 0 (pre-vaccination) from study JEC02, Day 28 post-vaccination from study JEC02, and at Years 1, 2, 3, 4, and 5 post-vaccination
Population: Seroprotection was analyzed in the Per Protocol Analysis Set.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| Study Group | Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Day 0 (pre-vaccination) | 2.6 Percentage of participants |
| Study Group | Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Day 28 post-vaccination | 100.0 Percentage of participants |
| Study Group | Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Year 1 post-vaccination | 88.2 Percentage of participants |
| Study Group | Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Year 2 post-vaccination | 90.0 Percentage of participants |
| Study Group | Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Year 3 post-vaccination | 93.1 Percentage of participants |
| Study Group | Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Year 4 post-vaccination | 87.6 Percentage of participants |
| Study Group | Percentage of Participants With Japanese Encephalitis Seroprotection Following a Single Dose of JE-CV | Year 5 post-vaccination | 85.4 Percentage of participants |
Primary
Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV
Geometric mean titers of Japanese encephalitis virus antibodies were assessed using the PRNT50 test.
Time frame: Day 0 (pre-vaccination) from JEC02, Day 28 post-vaccination from JEC02, and at Years 1, 2, 3, 4, and 5 post-vaccination
Population: Geometric mean titers were assessed in the Per Protocol Analysis Set.
| Arm | Measure | Group | Value (GEOMETRIC_MEAN) |
|---|---|---|---|
| Study Group | Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Day 0 (pre-vaccination) | 5.13 Titers (1/dil) |
| Study Group | Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Day 28 post-vaccination | 252 Titers (1/dil) |
| Study Group | Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Year 1 post-vaccination | 76.8 Titers (1/dil) |
| Study Group | Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Year 2 post-vaccination | 81.4 Titers (1/dil) |
| Study Group | Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Year 3 post-vaccination | 132 Titers (1/dil) |
| Study Group | Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Year 4 post-vaccination | 85.8 Titers (1/dil) |
| Study Group | Summary of Geometric Mean Titers of Japanese Encephalitis Virus Antibodies Following a Single Dose of a JE-CV | Year 5 post-vaccination | 63.3 Titers (1/dil) |