Immunogenicity and Safety of the Second Dose of Varicella Vaccine in Healthy Children: An Open-label Study

Sinovac (Dalian) Vaccine Technology Co., Ltd.5 个研究点分布在 1 个国家目标入组 300 人开始时间: 2026年1月28日最近更新: 2026年3月16日

干预措施

试验速览

阶段: 3 期
状态: 招募中
发起方: Sinovac (Dalian) Vaccine Technology Co., Ltd.
入组人数: 300
试验地点: 5
主要终点: Geometric Mean Concentration (GMC) of Varicella-Zoster Virus (VZV) Antibodies

研究概览研究设计入排标准研究组 & 干预措施结局指标研究者研究点记录与标识符相似试验

研究概览

简要总结

This study aim to assess the immunogenicity and safety of interchangeable administration of the second dose of varicella vaccine. A total of 300 healthy participants aged 15 months - 12 years will be enrolled. Written informed consent form will be obtained from participants' parents or legally acceptable representatives (and assents will be obtained from participants aged above 9 years old and written consent forms will be prepared and consent will be obtained in writing if possible from the participants aged 3-8 years old.) before enrollment. Participants will be assigned to 5 groups according to the brand of first dose varicella vaccine they received at the age of 12 months. All participants will receive the second dose of varicella vaccine manufactured by Sinovac.

The duration of individual participation from enrollment to the last onsite visit will be a maximum of 42 days. The end of study is considered the completion of the last visit for the last participant in this study.

Blood samples (2.5 - 3.0ml per time) for immunogenicity assessment will be collected. The blood samples will be collected before vaccination and 42 days after vaccination.

研究设计

研究类型: Interventional
分配方式: Non Randomized
干预模型: Parallel
主要目的: Prevention
盲法: None

入排标准

年龄范围: 15 Months 至 12 Years（Child）
性别: All
接受健康志愿者: 是

入选标准

•Healthy children aged 15 months to 12 years.
•Have received one dose of varicella vaccine at 12 months of age in Turkey (verified by vaccination card or official electronic immunization record).
•Written informed consent obtained from parent(s) or legally authorized representative(s); assent obtained from children as applicable according to local regulations.
•Able to comply with study procedures, as assessed by the investigator.
•Able to provide verifiable identification and be contacted for study follow-up during the study period.

排除标准

•History of varicella-zoster virus (VZV) infection (based on parental report or medical record).
•Known exposure to VZV within 4 weeks prior to screening.
•Receipt of more than one dose of varicella vaccine.
•Interval between first dose of varicella vaccine and enrollment less than 3 months.
•Known allergy to any vaccine component or history of severe allergic reaction to any vaccine (e.g., urticaria, dyspnea, angioedema).
•Known or suspected immunodeficiency or autoimmune disease (including but not limited to systemic lupus erythematosus, ankylosing spondylitis, autoimmune thyroid disease, asplenia, functional asplenia, or HIV infection).
•Poorly controlled chronic disease or history of severe systemic disease.
•Current or history of severe neurological disorders (e.g., epilepsy, convulsions or seizures excluding simple febrile seizures) or psychiatric disorders.
•Receipt of ≥14 days of immunosuppressive or immunomodulatory therapy (e.g., prednisone ≥20 mg/day or ≥2 mg/kg/day or equivalent), or cytotoxic therapy within 180 days prior to screening, or planned use during the study period.
•Receipt of blood products or immunoglobulins within 180 days prior to screening, or planned receipt during the study period.
•Receipt of other investigational drugs or vaccines within 30 days prior to screening, or planned receipt during the study period.
•Receipt of live attenuated or nucleic acid vaccines within 28 days prior to screening, or subunit or inactivated vaccines within 7 days prior to screening.
•Fever (axillary temperature >37.2°C), abnormal vital signs, or clinically significant abnormal findings on physical examination on the day of vaccination.
•Skin conditions at the intended injection site (e.g., inflammation, ulceration, rash, scar, or other conditions that may interfere with administration or safety assessment).
•Acute illness or exacerbation of chronic disease within 7 days prior to vaccination, or known or suspected active infection.
•Any condition that, in the opinion of the investigator, would make the participant unsuitable for participation in the study.