Study of a Booster Dose of IMOJEV® One Year After Primary Immunization in Healthy Children in South Korea

Immunogenicity and Safety Exploration of a Booster Dose of a Live Attenuated Japanese Encephalitis Chimeric Virus Vaccine (IMOJEV®) Given One Year After Primary Immunization in Healthy Children in South Korea

Status

Completed

Phases

Phase 3

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01900444

Enrollment

119

Registered

2013-07-16

Start date

2013-07-11

Completion date

2014-03-11

Last updated

2022-03-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Japanese Encephalitis

Keywords

Japanese encephalitis, Japanese encephalitis chimeric virus vaccine, IMOJEV®

Brief summary

The aim of this study was to document the immunogenicity and safety of a booster dose of IMOJEV administered at least 12 months after the primary dose. Primary objective: * To describe the immune response to Japanese Encephalitis (JE) before and 28 days after a booster dose of IMOJEV administered at least 12 months after primary vaccination with IMOJEV. Exploratory objectives: * To describe the safety profile of a booster dose of IMOJEV® .

Detailed description

Participants who previously participated in Study JEC12 (NCT01396512) and were primed with IMOJEV received a booster dose of IMOJEV at least 12 months after the primary dose. Participants were assessed for immune response before and on Day 28 after the booster dose and were monitored for safety through Day 28 post-vaccination for non-serious adverse events (AEs) and up to 6 months post-vaccination for serious AEs The duration of each participant's participation in the study was approximately 6 months.

Interventions

BIOLOGICALIMOJEV

0.5 mL, Subcutaneous

Study design

Allocation

Intervention model

SINGLE_GROUP

Primary purpose

PREVENTION

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

2 Years to 4 Years

Healthy volunteers

Yes

Inclusion criteria

* Must have participated in study JEC12 and received 1 dose of IMOJEV at least 12 months before booster vaccination * Age 2 to 4 years on the day of inclusion * In good general health at the time of inclusion * Informed Concent Form signed and dated by parent(s) or another legally acceptable representative(s) * Subject and parent(s)/legally acceptable representative(s) able to attend all scheduled visits and comply with all study procedures.

Exclusion criteria

* Participation at the time of study enrollment (or in the 4 weeks preceding the trial vaccination) or planned participation during the present trial period in another clinical study investigating a vaccine, drug, medical device, or a medical procedure in the 4 weeks preceding the study vaccination * Known or suspected congenital or acquired immunodeficiency, or receipt of immunosuppressive therapy such as anti-cancer chemotherapy or radiation therapy within the preceding 6 months, or long-term systemic corticosteroids therapy * Known systemic hypersensitivity to any of the vaccine components, or history of a life-threatening reaction to the vaccine used in the trial or to a vaccine containing any of the same substances * Chronic illness that, in the opinion of the investigator, is at a stage where it might interfere with trial conduct or completion * Receipt of immune globulins, blood or blood-derived products in the past 3 months, that might interfere with the assessment of the immune response * Previous vaccination against flavivirus disease, including JE, with another vaccine, except with IMOJEV® while participating in JEC12 * Administration of any anti-viral within 2 months preceding Visit 1 and up to the 4 weeks following the study vaccination * Receipt of any vaccine in the 4 weeks preceding the trial vaccination or planned receipt of any vaccine in the 4 weeks following the trial vaccination, except for inactivated influenza vaccination, which may be received at least 2 weeks before the study vaccine * History of central nervous system disorder or disease, including seizures * Planned receipt of any JE vaccine during the course of the study * History of flavivirus infection (confirmed either clinically, serologically or virologically) * Administration of systemic corticosteroids for more than 2 consecutive weeks within the 4 weeks preceding vaccination * Thrombocytopenia, contraindicating vaccination * Bleeding disorder, or receipt of anticoagulants in the 3 weeks preceding inclusion, contraindicating vaccination * Febrile illness (temperature ≥38.0°C) or moderate or severe acute illness/infection 3 days before vaccination as well as the day of vaccination, according to Investigator judgment. A prospective subject should not be included in the study until the condition has resolved or the febrile event has subsided * In an emergency setting or hospitalized involuntarily * Identified as a natural or adopted child of the Investigator or employee with direct involvement in the proposed study.

Design outcomes

Primary

Measure	Time frame	Description
Percentage of Participants With JE Seroprotection Before and Following a Booster Dose of IMOJEV Given One Year After Primary Immunization	Day 0 (pre-booster) and Day 28 post-booster injection	JE virus neutralizing antibodies were measured using a 50% plaque reduction neutralization test (PRNT50). Seroprotection status for antibody levels against JE virus before and after IMOJEV vaccination was defined as antibody titers ≥ 10 (1/dilution).
Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given One Year After Primary Immunization	Day 28 post-booster injection	JE virus neutralizing antibodies were measured using PRNT50. Seroconversion was defined as a pre-vaccination titer \<10 (1/dilution) and post-vaccination titer ≥10 (1/dilution, or pre-vaccination titer ≥10 (1/dilution) and a ≥4-fold increase of titers from pre- to post-vaccination.
Summary of Geometric Mean Titers of JE Virus Antibodies Following a Booster Dose of IMOJEV Given One Year After Primary Immunization	Day 0 (pre-booster) and Day 28 post-booster injection	JE virus neutralizing antibodies were measured using PRNT50 test.
Summary of Geometric Mean Titer Ratios of JE Virus Antibodies Following a Booster Dose of IMOJEV Given One Year After Primary Immunization	Day 0 (pre-booster) and Day 28 post-booster injection	JE virus neutralizing antibodies were measured using PRNT50.
Percentage of Participants With JE Seroprotection Before and After a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization	Day 0 (pre-booster) and Day 28 post-booster injection	JE virus neutralizing antibodies were measured using PRNT50. Seroprotection was defined as neutralizing antibody titer ≥ 10 (1/dilution).
Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization	Day 28 post-booster injection	JE virus neutralizing antibodies were measured using PRNT50. Seroconversion was defined as a pre-vaccination titer \<10 (1/dilution) and post-vaccination titer ≥10 (1/dilution, or pre-vaccination titer ≥10 (1/dilution) and a ≥4 fold increase from pre- to post-vaccination.
Summary of Geometric Mean Titers of JE Virus Antibodies Following a Booster Dose of IMOJEV At Different Intervals After Primary Immunization	Day 0 (pre-booster) and Day 28 post-booster injection	JE virus neutralizing antibodies were measured using PRNT50.
Summary of Geometric Mean Titer Ratios of JE Virus Antibodies Following a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization	Day 0 (pre-booster) and Day 28 post-booster injection	JE virus neutralizing antibodies were measured using PRNT50.

Countries

South Korea

Participant flow

Recruitment details

Study participants were enrolled from 11 July 2013 to 27 September 2013 at 8 clinic centers in South Korea.

Pre-assignment details

A total of 119 participants who met all inclusion and no exclusion criteria were enrolled and vaccinated.

Participants by arm

Arm	Count
Japanese Encephalitis Chimeric Virus Vaccine (IMOJEV®) Participants 2 to 4 years of age received one booster dose of IMOJEV® 1 year after primary immunization.	119
Total	119

Withdrawals & dropouts

Period	Reason	FG000
Overall Study	Lost to Follow-up	1
Overall Study	Protocol Violation	2

Baseline characteristics

Characteristic	Japanese Encephalitis Chimeric Virus Vaccine (IMOJEV®)
Age, Categorical <=18 years	119 Participants
Age, Categorical >=65 years	0 Participants
Age, Categorical Between 18 and 65 years	0 Participants
Age, Continuous	2.62 Years STANDARD_DEVIATION 0.391
Region of Enrollment South Korea	119 Participants
Sex: Female, Male Female	48 Participants
Sex: Female, Male Male	71 Participants

Adverse events

Event type	EG000 affected / at risk
deaths Total, all-cause mortality	0 / 119
other Total, other adverse events	48 / 119
serious Total, serious adverse events	4 / 119

Outcome results

Primary

Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization

JE virus neutralizing antibodies were measured using PRNT50. Seroconversion was defined as a pre-vaccination titer \<10 (1/dilution) and post-vaccination titer ≥10 (1/dilution, or pre-vaccination titer ≥10 (1/dilution) and a ≥4 fold increase from pre- to post-vaccination.

Time frame: Day 28 post-booster injection

Population: Seroconversion rates were assessed in the Per Protocol Analysis Set.

Arm	Measure	Group	Value (NUMBER)
Japanese Encephalitis Chimeric Virus Vaccine (IMOJEV®)	Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization	Post-Booster; ≥12 months and <18 months	96.2 Percentage of participants
Japanese Encephalitis Chimeric Virus Vaccine (IMOJEV®)	Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization	Post-Booster; ≥18 months and <24 months	92.1 Percentage of participants
Japanese Encephalitis Chimeric Virus Vaccine (IMOJEV®)	Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization	Post-Booster; ≥24 months	100.0 Percentage of participants

Primary

Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given One Year After Primary Immunization

Time frame: Day 28 post-booster injection

Population: Seroconversion rates were assessed in the Per Protocol Analysis Set.

Arm	Measure	Value (NUMBER)
Japanese Encephalitis Chimeric Virus Vaccine (IMOJEV®)	Percentage of Participants With JE Seroconversion Following a Booster Dose of IMOJEV Given One Year After Primary Immunization	94.6 Percentage of participants

Primary

Percentage of Participants With JE Seroprotection Before and After a Booster Dose of IMOJEV Given At Different Intervals After Primary Immunization

JE virus neutralizing antibodies were measured using PRNT50. Seroprotection was defined as neutralizing antibody titer ≥ 10 (1/dilution).