Seroprevalence of Neutralizing Antibodies Against Japanese Encephalitis Virus Among 6 Years Old Children With 5 Different Immunization Strategies in Zhejiang Province
1 other identifier
interventional
712
1 country
3
Brief 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). 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.
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for phase_4
Started Mar 2021
Typical duration for phase_4
3 active sites
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
Study Start
First participant enrolled
March 1, 2021
CompletedFirst Submitted
Initial submission to the registry
March 23, 2021
CompletedFirst Posted
Study publicly available on registry
March 26, 2021
CompletedPrimary Completion
Last participant's last visit for primary outcome
September 17, 2022
CompletedStudy Completion
Last participant's last visit for all outcomes
June 30, 2023
CompletedNovember 15, 2022
July 1, 2022
1.5 years
March 23, 2021
November 13, 2022
Conditions
Keywords
Outcome Measures
Primary Outcomes (2)
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.
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).
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
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.
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.
28-35 days after the booster dose.
Safety of the booster dose for Group 1 and Group 2
From inoculation to 30 days after the inoculation.
Study Arms (5)
3JEV-I (Group 1)
EXPERIMENTALRetrospective: 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)
EXPERIMENTALRetrospective: 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)
EXPERIMENTALRetrospective: 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)
EXPERIMENTALRetrospective: 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)
EXPERIMENTALRetrospective: 2 doses of JE vaccines. 2 doses of JEV-L respectively administered at 8 months of age and 2 years old.
Interventions
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.
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.
Eligibility Criteria
You may qualify if:
- 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.
You may not qualify if:
- 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.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
Study Sites (3)
Liandu center for disease control and prevention
Lishui, Zhejiang, 323000, China
Kecheng center for disease control and prevention
Quzhou, Zhejiang, 324000, China
Pingyang center for disease control and prevention
Wenzhou, Zhejiang, 325400, China
MeSH Terms
Conditions
Interventions
Condition Hierarchy (Ancestors)
Intervention Hierarchy (Ancestors)
Study Design
- Study Type
- interventional
- Phase
- phase 4
- Allocation
- NON RANDOMIZED
- Masking
- NONE
- Purpose
- PREVENTION
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER GOV
- Responsible Party
- SPONSOR
Study Record Dates
First Submitted
March 23, 2021
First Posted
March 26, 2021
Study Start
March 1, 2021
Primary Completion
September 17, 2022
Study Completion
June 30, 2023
Last Updated
November 15, 2022
Record last verified: 2022-07