Japanese Encephalitis VaccinePhase 4NCT06825312
Immunogenicity, Safety, and Antibody Persistence of Different Immunization Strategies Against Japanese Encephalitis
A Phase 4 study testing Japanese Encephalitis Vaccine (Vero Cell), Inactivated and Japanese Encephalitis Vaccine, Live in people with Japanese Encephalitis Vaccine, run by Liaoning Chengda Biotechnology CO., LTD at 6 sites in China.
Trial summary
The main objective of this study is to evaluate the persistence of Japanese encephalitis antibodies in participants at the age of 6, after they have followed different Japanese encephalitis vaccination schedules. Read more about this study
- Who is it for?
- Ages 8 to 8 monthsHealthy volunteers can take part
- Conditions the study is for
- Japanese Encephalitis Vaccine
- What is being tested?
- Japanese Encephalitis Vaccine (Vero Cell), Inactivated and Japanese Encephalitis Vaccine, Live
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 600 participants
- Where
- 6 sitesChina
- Study dates
- 11 Nov 2023to 31 Dec 2031
- Phase
- Phase 4
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 8 to 8 months
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Healthy children aged 8 months who are permanent residents of the study area.
- Legal guardians can understand the requirements and processes of the study, provide written informed consent, and comply with all procedures as required by the clinical research protocol.
- Able to receive the full course of Japanese encephalitis vaccinations according to the immunization strategy in the research protocol, including receiving the primary immunization at 8 months of age and the booster immunizations at 24 months of age and 6 years of age.
Who cannot join
- Unable to finish the full course of primary and booster immunizations at the study area, and unable to fulfill the follow-up visits prescribed in the protocol.
- Non-compliance with the vaccination strategy for each group, as stated in the protocol, regarding Japanese encephalitis vaccines with proper doses and varieties.
- Allergic to any component of the study vaccine or having a history of allergic reactions to any vaccines.
- Having a history of symptoms or signs of neurological diseases or other contraindications for Japanese encephalitis vaccine vaccination.
- Having used immunosuppressants or blood products following birth.
- Receiving other vaccines simultaneously while receiving the Japanese encephalitis vaccine of this project.
- Any conditions that may interfere with the evaluation of the study, as deemed by the researcher.
Trial locations and contacts
6 sites in 1 country.
6 sites in 1 country
China6 sites
Jiashan County Center for Disease Control and Prevention
Jiaxing, Zhejiang
Pinghu Center For Disease Control and Prevention
Jiaxing, Zhejiang
Dongyang Center for Disease Control and Prevention
Jinhua, Zhejiang
Yongkang Center for Disease Control and Prevention
Jinhua, Zhejiang
Yuyao Center for Disease Control and Prevention
Ningbo, Zhejiang
Jiangshan Center For Disease Control and Prevention
Quzhou, Zhejiang
About this study
The main objective of this study is to evaluate the persistence of Japanese encephalitis antibodies in participants at the age of 6, after they have followed different Japanese encephalitis vaccination schedules. Furthermore, the study will assess the immunogenicity and antibody persistence of primary immunization across different Japanese encephalitis vaccination schedules, as well as the immunogenicity following booster immunizations within these schedules. The safety of each vaccine dose will also be evaluated.
Read the detailed description
This is a randomized, controlled, open-label, non-inferiority study. Healthy children aged 8 months will be invited to participate and randomly allocated to six groups (Group 1 to Group 6) in a 1:1:1:1:1:1 ratio. They will be administered the inactivated Japanese encephalitis vaccine (JEV-I) and/or the live attenuated Japanese encephalitis vaccine (JEV-L) based on the six schedules delineated in the protocol. The primary immunization will be administered to participants at 8 months of age, and a booster dose will be given at 24 months of age. Additionally, participants in Groups 1, 2, and 5 will receive an additional booster dose at the age of 6.
Blood samples (3 mL) will be collected from participants at 8 months, 24 months, and 6 years of age. Samples will be taken before vaccination and 30 days after it for detecting Japanese encephalitis neutralizing antibodies. The titers of these antibodies will be assayed via the 50% plaque reduction neutralization test. Those in groups 3, 4, and 6 who've completed all immunization procedures by 24 months old will have a blood sample taken at 6 years old.
- Conditions
- Japanese Encephalitis Vaccine
- Being tested
- Japanese Encephalitis Vaccine (Vero Cell), Inactivated, Japanese Encephalitis Vaccine, Live
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Japanese Encephalitis Vaccine (Vero Cell), InactivatedBiological
0.5ml for each dose, manufactured by Liaoning Chengda Biotechnology Co., Ltd., administered in the deltoid area of lateral arm by intramuscular injection.
Japanese Encephalitis Vaccine, LiveBiological
0.5ml for each dose, manufactured by Chengdu Institute of Biological Products Co., Ltd., administered subcutaneously in the lower part of the deltoid area of lateral arm.
| Study group | Role | What they receive |
|---|---|---|
| Group 1 (4 doses of JEV-I) | Experimental | Participants will receive 2 doses of JEV-I (7-10 days apart) at 8 months of age, 1 dose of JEV-I at 24 months of age, and 1 dose of JEV-I at 6 years of age. Receives: Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated |
| Group 2 (4 doses of JEV-I) | Experimental | Participants will receive 2 doses of JEV-I (28-35 days apart) at 8 months of age, 1 dose of JEV-I at 24 months of age, and 1 dose of JEV-I at 6 years of age. Receives: Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated |
| Group 3 (2 doses of JEV-I and 1 dose of JEV-L) | Experimental | Participants will receive 2 doses of JEV-I (7-10 days apart) at 8 months of age and 1 dose of JEV-L at 24 months of age. Receives: Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated; Biological: Japanese Encephalitis Vaccine, Live |
| Group 4 (1 dose of JEV-L and 2 doses of JEV-I) | Experimental | Participants will receive 1 dose of JEV-L at 8 months of age and 2 doses of JEV-I (7-10 days apart) at 24 months of age. Receives: Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated; Biological: Japanese Encephalitis Vaccine, Live |
| Group 5 (1 dose of JEV-L and 2 doses of JEV-I) | Experimental | Participants will receive 1 dose of JEV-L at 8 months of age, 1 dose of JEV-I at 24 months of age, and 1 dose of JEV-I at 6 years of age. Receives: Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated; Biological: Japanese Encephalitis Vaccine, Live |
| Group 6 (2 doses of JEV-L) | Active comparator | Participants will receive 2 doses of JEV-L at 8 months of age, and 1 dose of JEV-L at 24 months of age. Receives: Biological: Japanese Encephalitis Vaccine, Live |
What is being measured
The primary outcome is the main question the study is designed to answer.
Percentage of Participants Testing Seropositive for Japanese Encephalitis Neutralizing Antibodies
The persistence of immunity following various Japanese encephalitis (JE) vaccination schedules is evaluated based on the proportion of participants exhibiting seropositivity for JE neutralizing antibodies at 6 years of age. Seropositivity is defined as a JE neutralizing antibody titer of at least 1:10, as ascertained by the 50% plaque reduction neutralization test.
Measured: 4 years after the booster vaccination at 24 months of age
Secondary outcomes (7)
Seroconversion Rates of Japanese Encephalitis Neutralizing Antibodies after Primary vaccination
The seroconversion rate is defined as the percentage of participants with a change in Japanese Encephalitis neutralizing antibody titer from <1:10 at baseline (pre-vaccination) to a titer of ≥1:10 30 days post-vaccination, or a 4-fold or greater rise from the baseline, as measured by the 50% plaque reduction neutralization test
Measured: 30 days post-primary immunization
Geometric Mean Titer of Japanese Encephalitis Neutralizing Antibodies before and after Primary Immunization
Measured: pre-primary immunization (Day 0) and 30 days post-primary immunization
Percentage of Participants Testing Seropositive for Japanese Encephalitis Neutralizing Antibodies before and after Primary Immunization
Seropositivity is defined as a Japanese Encephalitis neutralizing antibody titer of at least 1:10, as ascertained by the 50% plaque reduction neutralization test.
Measured: pre-primary immunization (Day 0) and 30 days post-primary immunization
Seroconversion Rates of Japanese Encephalitis Neutralizing Antibodies after Booster vaccination
The seroconversion rate is defined as the percentage of participants with a change in Japanese Encephalitis neutralizing antibody titer from <1:10 at baseline (pre-vaccination) to a titer of ≥1:10 30 days post-vaccination, or a 4-fold or greater rise from the baseline, as measured by the 50% plaque reduction neutralization test
Measured: 30 days post-booster immunization
Geometric Mean Titer of Japanese Encephalitis Neutralizing Antibodies before and after booster Immunization
Measured: pre-booster immunization (Day 0) and 30 days post-booster immunization
Percentage of Participants Testing Seropositive for Japanese Encephalitis Neutralizing Antibodies before and after booster Immunization
Seropositivity is defined as a Japanese Encephalitis neutralizing antibody titer of at least 1:10, as ascertained by the 50% plaque reduction neutralization test.
Measured: pre-booster immunization (Day 0) and 30 days post-booster immunization
Incidence of any Local and Systemic Adverse Events Within 30 Days of Each Vaccination
Adverse events will be collected through a combination of proactive visits by researchers and participant reports
Measured: within 30 days of each vaccination
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Feb 2025
- Study start11 Nov 2023
- Primary completion31 Dec 2030 (estimated)
- Study completion31 Dec 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Japanese Encephalitis VaccineStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 600 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Liaoning Chengda Biotechnology CO., LTD
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Zhejiang Provincial Center for Disease Control and Prevention
- Responsible party
- Sponsor
- Investigators
- Huanyu Wang, Study director, Liaoning Chengda Biotechnology CO., LTD
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06825312
- Sponsor's protocol ID
- CDB-JE-PM-2023002
- Status last verified
- Aug 2026
- First submitted
- 9 Feb 2025
- Last updated
- 2 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No