Japanese EncephalitisPhase 4NCT04817917
Seroprevalence of Neutralizing Antibodies Against Japanese Encephalitis Virus Among 6 Years Old Children With 5 Different Immunization Strategies in Zhejiang Province
A Phase 4 study testing Japanese Encephalitis Vaccine (Vero Cell), Inactivated; and No prospective interventions in people with Japanese Encephalitis and Vaccine Preventable Disease, run by Zhejiang Provincial Center for Disease Control and Prevention at 3 sites in China.
Trial summary
This study is to evaluate the seroprevalence of neutralizing antibodies against Japanese encephalitis (JE) virus in children aged 6 years who were previously administered with 5 different immunization strategies by JE attenuated live vaccine (JEV-L) or/and inactivated vaccine (JEV-I). Read more about this study
- Who is it for?
- Ages 72 to 75 monthsHealthy volunteers can take part
- Conditions the study is for
- Japanese Encephalitis, Vaccine Preventable Disease, Vaccine Reaction
- What is being tested?
- Japanese Encephalitis Vaccine (Vero Cell), Inactivated; and No prospective interventions
- Type of treatment
- Vaccines
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 712 participants
- Where
- 3 sitesChina
- Study dates
- 1 Mar 2021to 30 Jun 2023
- Phase
- Phase 4
- Are there results?
- None posted in the registry
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 72 to 75 months
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Participants aged ≥ 72 months to < 75 months.
- Participants have completed routine immunization schedules in time.
- Participants are healthy native residents.
- Parents/guardians can understand the protocol requirements, provide informed consent, accept all scheduled visits, and comply with all trial procedures.
Who cannot join
- History of neurological diseases or related symptoms.
- An acute illness with fever (temperature ≥ 37.1℃) or any acute onset of chronic diseases.
- Known impairment of immunologic function, or receipt of immunosuppressive therapy or immunoglobulin in the past 3 months.
- Known allergy to any constituent of the vaccine.
- Have been injected with other vaccines or any clinical trial drugs in the past 4 weeks.
- Any condition which, in the opinion of the investigator, would pose a health risk to the subject or interfere with the vaccine.
Trial locations and contacts
3 sites in 1 country.
China3 sites
Liandu center for disease control and prevention
Lishui, Zhejiang, 323000
Kecheng center for disease control and prevention
Quzhou, Zhejiang, 324000
Pingyang center for disease control and prevention
Wenzhou, Zhejiang, 325400
About this study
Official title: Seroprevalence of Neutralizing Antibodies Against Japanese Encephalitis Virus Among 6 Years Old Children With 5 Different Immunization Strategies in Zhejiang Province, China: An Open-labeled, Ambidirectional Cohort Study
This study is to evaluate the seroprevalence of neutralizing antibodies against Japanese encephalitis (JE) virus in children aged 6 years who were previously administered with 5 different immunization strategies by JE attenuated live vaccine (JEV-L) or/and inactivated vaccine (JEV-I). The secondary objective is to evaluate the immunogenicity of the booster dose of JEV-I at 6 years old for those previously immunized with 3 doses of JEV-I or those sequential administered with 1 dose of JEV-L and another dose of JEV-I.
Read the detailed description
Based on the retrospective registry in Zhejiang Provincial Immunization Information System, healthy children aged 6 years from 5 cohorts were included according to their previous immunization schedules on JE: 3 doses of JEV-I (Group 1), JEV-L+ JEV-I (Group 2), JEV-L+ JEV-I + JEV-I (Group 3), JEV-I + JEV-I+ JEV-L (Group 4), and 2 doses of JEV-L (Group 5). According to immunization programs in China, a booster dose of JEV-I is needed at the age of 6 for Group 1 and Group 2. A pre-vaccination blood sample (2.5ml) will be collected to evaluate the proportions of seropositivity before the booster dose of JEV-I. A second blood sample will be collected 28-35 days after the booster dose. Immunogenicity of the booster dose will be assessed by seroconversion rates, proportions of seropositivity and GMTs for these two groups. In addition, safety will be assessed with the occurrence of adverse events reported in these two groups. For the rest three groups who have completed the immunization schedules on JE, only one blood sample will be taken at the age of 6 to evaluate the proportions of seropositivity and GMTs after 4 years post the complete immunization schedules. Plague reduction neutralization test (PRNT) against both vaccine strains (SA-14-14-2 strain for JEV-L and Beijing P3 strain for JEV-I) will be used to test neutralizing antibody titers, so as to avoid potential bias in favor of either vaccine. PRNT50 titers (the reciprocal of the serum dilution that reduced the virus plaque count by 50% compared with the virus-only controls) ≥ 1:10 are deemed as positive.
- Being tested
- Japanese Encephalitis Vaccine (Vero Cell), Inactivated;, No prospective interventions
- Keywords
- Japanese Encephalitis, Seroprevalence, Immunogenicity, Immunization schedule, Safety
- Medical subject headings
- Encephalitis, Japanese, Vaccine-Preventable Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Japanese Encephalitis Vaccine (Vero Cell), Inactivated;Biological
The investigators recruit 6 years old children who have been vaccinated by 2-3 doses of JE vaccines with different immunization strategies. For participants from Group 1 and Group 2 who haven't completed the JE immunization schedules, a booster dose of JEV-I will be administered at 6 years old.
No prospective interventionsOther
The investigators recruit 6 years old children who have been vaccinated by 2-3 doses of JE vaccines with different immunization strategies. Participants from Group 3-5 have completed the JE immunization schedules with JEV-I or/and JEV-L. No prospective intervention will be given.
| Study group | Role | What they receive |
|---|---|---|
| 3JEV-I (Group 1) | Experimental | Retrospective: 3 doses of JE vaccines. 2 doses of Inactivated JE Vaccine (JEV-I, 7-10 days apart) at 8 months of age and 1 dose of JEV-I at 2 years old.
Prospective: 1 booster dose of JEV-I at 6 years old. Receives: Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated; |
| JEV-L+JEV-I (Group 2) | Experimental | Retrospective: 2 doses of JE vaccines.
1 dose of JE attenuated live vaccine (JEV-L) at 8 months of age and 1 dose of JEV-I at 2 years old.
Prospective: 1 booster dose of JEV-I at 6 years old. Receives: Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated; |
| JEV-L+2JEV-I (Group 3) | Experimental | Retrospective: 3 doses of JE vaccines.
1 dose of JEV-L at 8 months of age and 2 dose (7-10 days apart) of JEV-I at 2 years old. Receives: Other: No prospective interventions |
| 2JEV-I+JEV-L (Group 4) | Experimental | Retrospective: 3 doses of JE vaccines. 2 doses of JEV-I (7-10 days apart) at 8 months of age and 1 dose of JEV-L at 2 years old. Receives: Other: No prospective interventions |
| 2JEV-L (Group 5) | Experimental | Retrospective: 2 doses of JE vaccines. 2 doses of JEV-L respectively administered at 8 months of age and 2 years old. Receives: Other: No prospective interventions |
What is being measured
The primary outcome is the main question the study is designed to answer.
Proportions of seropositivity of neutralizing antibodies against JE at the age of 6
Defined as any positive antibody (neutralizing antibody titers ≥1:10) response in children aged 6.
Measured: At the age of 6. Test immediately after enrollment by a dose of blood sample.
Geometric Mean Titers (GMTs) or Median antibody titers for children aged 6 years
Neutralizing antibody titers by plaque-reduction neutralization tests (PRNT).
Measured: At the age of 6. Test immediately after enrollment by a dose of blood sample.
Secondary outcomes (4)
Seroconversion rates of the booster dose of JEV-I for Group 1 and Group 2
Defined as any positive antibody (neutralizing antibody titers ≥1:10) response in children who were seronegative prior to the booster dose, or at least a four-fold increase for children who had pre-existing positive antibodies.
Measured: before and 28-35 days after the booster dose.
Proportion of seropositivity of neutralizing antibodies against JE after the booster dose for Group 1 and Group 2.
Defined as any positive antibody (neutralizing antibody titers ≥1:10) response after the booster dose.
Measured: 28-35 days after the booster dose.
Geometric Mean Titers (GMTs) or Median antibody titers after the booster dose for Group 1 and Group 2.
Neutralizing antibody titers by PRNT.
Measured: 28-35 days after the booster dose.
Safety of the booster dose for Group 1 and Group 2
The occurrence of adverse events for the booster dose
Measured: From inoculation to 30 days after the inoculation.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Mar 2021
- Study start1 Mar 2021
- Primary completion17 Sep 2022
- Study completion30 Jun 2023 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Japanese EncephalitisStudies 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
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 712 participants (actual)
Sponsor and investigators
- Lead sponsor
- Zhejiang Provincial Center for Disease Control and Prevention
- Sponsor type
- Other government
- Collaborators
- Liaoning Chengda Biotechnology CO., LTD
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04817917
- Sponsor's protocol ID
- ZJCDC20210317
- Status last verified
- Jul 2022
- First submitted
- 23 Mar 2021
- Last updated
- 15 Nov 2022
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Nov 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Seroprevalence of Neutralizing Antibodies Against Japanese Encephalitis Virus Among 6 Years Old Children With 5 Different Immunization Strategies in Zhejiang Province, China: An Open-labeled, Ambidirectional Cohort Study
- ClinicalTrials.gov ID
- NCT04817917
- Acronym / sponsor ID
- ZJCDC20210317
- Keywords
- Japanese Encephalitis, Seroprevalence, Immunogenicity, Immunization schedule, Safety
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 712 participants (actual)
- Lead sponsor
- Zhejiang Provincial Center for Disease Control and PreventionOther government
- Collaborators
- Liaoning Chengda Biotechnology CO., LTD
- Study start
- 1 Mar 2021 (actual)
- Primary completion
- 17 Sep 2022 (actual)
- Study completion
- 30 Jun 2023 (estimated)
- First posted
- 26 Mar 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is to evaluate the seroprevalence of neutralizing antibodies against Japanese encephalitis (JE) virus in children aged 6 years who were previously administered with 5 different immunization strategies by JE attenuated live vaccine (JEV-L) or/and inactivated vaccine (JEV-I). The secondary objective is to evaluate the immunogenicity of the booster dose of JEV-I at 6 years old for those previously immunized with 3 doses of JEV-I or those sequential administered with 1 dose of JEV-L and another dose of JEV-I.
Detailed description
Based on the retrospective registry in Zhejiang Provincial Immunization Information System, healthy children aged 6 years from 5 cohorts were included according to their previous immunization schedules on JE: 3 doses of JEV-I (Group 1), JEV-L+ JEV-I (Group 2), JEV-L+ JEV-I + JEV-I (Group 3), JEV-I + JEV-I+ JEV-L (Group 4), and 2 doses of JEV-L (Group 5). According to immunization programs in China, a booster dose of JEV-I is needed at the age of 6 for Group 1 and Group 2. A pre-vaccination blood sample (2.5ml) will be collected to evaluate the proportions of seropositivity before the booster dose of JEV-I. A second blood sample will be collected 28-35 days after the booster dose. Immunogenicity of the booster dose will be assessed by seroconversion rates, proportions of seropositivity and GMTs for these two groups. In addition, safety will be assessed with the occurrence of adverse events reported in these two groups. For the rest three groups who have completed the immunization schedules on JE, only one blood sample will be taken at the age of 6 to evaluate the proportions of seropositivity and GMTs after 4 years post the complete immunization schedules. Plague reduction neutralization test (PRNT) against both vaccine strains (SA-14-14-2 strain for JEV-L and Beijing P3 strain for JEV-I) will be used to test neutralizing antibody titers, so as to avoid potential bias in favor of either vaccine. PRNT50 titers (the reciprocal of the serum dilution that reduced the virus plaque count by 50% compared with the virus-only controls) ≥ 1:10 are deemed as positive.
Study design
- Primary purpose
- Prevention
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| 3JEV-I (Group 1) | Experimental | Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated;Retrospective: 3 doses of JE vaccines. 2 doses of Inactivated JE Vaccine (JEV-I, 7-10 days apart) at 8 months of age and 1 dose of JEV-I at 2 years old. Prospective: 1 booster dose of JEV-I at 6 years old. |
| JEV-L+JEV-I (Group 2) | Experimental | Biological: Japanese Encephalitis Vaccine (Vero Cell), Inactivated;Retrospective: 2 doses of JE vaccines. 1 dose of JE attenuated live vaccine (JEV-L) at 8 months of age and 1 dose of JEV-I at 2 years old. Prospective: 1 booster dose of JEV-I at 6 years old. |
| JEV-L+2JEV-I (Group 3) | Experimental | Other: No prospective interventionsRetrospective: 3 doses of JE vaccines. 1 dose of JEV-L at 8 months of age and 2 dose (7-10 days apart) of JEV-I at 2 years old. |
| 2JEV-I+JEV-L (Group 4) | Experimental | Other: No prospective interventionsRetrospective: 3 doses of JE vaccines. 2 doses of JEV-I (7-10 days apart) at 8 months of age and 1 dose of JEV-L at 2 years old. |
| 2JEV-L (Group 5) | Experimental | Other: No prospective interventionsRetrospective: 2 doses of JE vaccines. 2 doses of JEV-L respectively administered at 8 months of age and 2 years old. |
Who may qualify
- Ages
- 72 to 75 months
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (4 listed)
- Participants aged ≥ 72 months to < 75 months.
- Participants have completed routine immunization schedules in time.
- Participants are healthy native residents.
- Parents/guardians can understand the protocol requirements, provide informed consent, accept all scheduled visits, and comply with all trial procedures.
Key exclusion criteria (6 listed)
- History of neurological diseases or related symptoms.
- An acute illness with fever (temperature ≥ 37.1℃) or any acute onset of chronic diseases.
- Known impairment of immunologic function, or receipt of immunosuppressive therapy or immunoglobulin in the past 3 months.
- Known allergy to any constituent of the vaccine.
- Have been injected with other vaccines or any clinical trial drugs in the past 4 weeks.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Japanese Encephalitis Vaccine (Vero Cell), Inactivated;The investigators recruit 6 years old children who have been vaccinated by 2-3 doses of JE vaccines with different immunization strategies. For participants from Group 1 and Group 2 who haven't completed the JE immunization schedules, a booster dose of JEV-I will be administered at 6 years old. | Biological | 3JEV-I (Group 1), JEV-L+JEV-I (Group 2) |
| No prospective interventionsThe investigators recruit 6 years old children who have been vaccinated by 2-3 doses of JE vaccines with different immunization strategies. Participants from Group 3-5 have completed the JE immunization schedules with JEV-I or/and JEV-L. No prospective intervention will be given. | Other | 2JEV-I+JEV-L (Group 4), 2JEV-L (Group 5), JEV-L+2JEV-I (Group 3) |
Primary outcome
Proportions of seropositivity of neutralizing antibodies against JE at the age of 6
Time frame: At the age of 6. Test immediately after enrollment by a dose of blood sample.
Defined as any positive antibody (neutralizing antibody titers ≥1:10) response in children aged 6.
Geometric Mean Titers (GMTs) or Median antibody titers for children aged 6 years
Time frame: At the age of 6. Test immediately after enrollment by a dose of blood sample.
Neutralizing antibody titers by plaque-reduction neutralization tests (PRNT).
4 secondary outcomes
Seroconversion rates of the booster dose of JEV-I for Group 1 and Group 2
Time frame: before and 28-35 days after the booster dose.
Proportion of seropositivity of neutralizing antibodies against JE after the booster dose for Group 1 and Group 2.
Time frame: 28-35 days after the booster dose.
Geometric Mean Titers (GMTs) or Median antibody titers after the booster dose for Group 1 and Group 2.
Time frame: 28-35 days after the booster dose.
Safety of the booster dose for Group 1 and Group 2
Time frame: From inoculation to 30 days after the inoculation.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Nov 2022.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
3 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Japanese Encephalitis Vaccine (Vero Cell), Inactivated; and No prospective interventions in people with Japanese Encephalitis and Vaccine Preventable Disease, run by Zhejiang Provincial Center for Disease Control and Prevention at 3 sites in China.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: status not confirmed, as of the sponsor's last update on 15 Nov 2022. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 3 sites in China. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Proportions of seropositivity of neutralizing antibodies against JE at the age of 6 (time frame: At the age of 6. Test immediately after enrollment by a dose of blood sample.). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Nov 2022.