Immunogenicity, Safety, and Antibody Persistence of Different Immunization Strategies Against Japanese Encephalitis
试验速览
- 阶段
- 4 期
- 状态
- 进行中（未招募）
- 入组人数
- 600
- 试验地点
- 6
- 主要终点
- Percentage of Participants Testing Seropositive for Japanese Encephalitis Neutralizing Antibodies
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 年龄范围
- 8 Months 至 8 Months（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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.
研究组 & 干预措施
Group 1 (4 doses of JEV-I)
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.
干预措施: Japanese Encephalitis Vaccine (Vero Cell), Inactivated (Biological)
Group 6 (2 doses of JEV-L)
Participants will receive 2 doses of JEV-L at 8 months of age, and 1 dose of JEV-L at 24 months of age.
干预措施: Japanese Encephalitis Vaccine, Live (Biological)
Group 5 (1 dose of JEV-L and 2 doses of JEV-I)
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.
干预措施: Japanese Encephalitis Vaccine, Live (Biological)
Group 2 (4 doses of JEV-I)
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.
干预措施: Japanese Encephalitis Vaccine (Vero Cell), Inactivated (Biological)
Group 3 (2 doses of JEV-I and 1 dose of JEV-L)
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.
干预措施: Japanese Encephalitis Vaccine (Vero Cell), Inactivated (Biological)
Group 3 (2 doses of JEV-I and 1 dose of JEV-L)
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.
干预措施: Japanese Encephalitis Vaccine, Live (Biological)
Group 4 (1 dose of JEV-L and 2 doses of JEV-I)
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.
干预措施: Japanese Encephalitis Vaccine (Vero Cell), Inactivated (Biological)
Group 4 (1 dose of JEV-L and 2 doses of JEV-I)
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.
干预措施: Japanese Encephalitis Vaccine, Live (Biological)
Group 5 (1 dose of JEV-L and 2 doses of JEV-I)
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.
干预措施: Japanese Encephalitis Vaccine (Vero Cell), Inactivated (Biological)
结局指标
主要结局
Percentage of Participants Testing Seropositive for Japanese Encephalitis Neutralizing Antibodies
时间窗: 4 years after the booster vaccination at 24 months of age
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.
次要结局
- Seroconversion Rates of Japanese Encephalitis Neutralizing Antibodies after Primary vaccination(30 days post-primary immunization)
- Geometric Mean Titer of Japanese Encephalitis Neutralizing Antibodies before and after Primary Immunization(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(pre-primary immunization (Day 0) and 30 days post-primary immunization)
- Seroconversion Rates of Japanese Encephalitis Neutralizing Antibodies after Booster vaccination(30 days post-booster immunization)
- Geometric Mean Titer of Japanese Encephalitis Neutralizing Antibodies before and after booster Immunization(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(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(within 30 days of each vaccination)