Clinical trial NCT06994052: Study on Booster Immunization With Varicella Vaccine at Different Intervals
Official title: A Phase Ⅳ Clinical Trial to Evaluate the Immunogenicity and Safety of Booster Immunization With Varicella Vaccine at Different Intervals Among Children Aged 7-12 Years
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: VZV
Varicella Immunisation
Lead sponsor: Sinovac (Dalian) Vaccine Technology Co., Ltd.
Sponsor class: INDUSTRY
First posted: 2025-05-29
Enrollment: 412
Sex: ALL
Minimum age (years): 7
Maximum age (years): 12
Standard ages: CHILD
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: PREVENTION

Brief summary: The goal of this clinical trial is to evaluate the immunogenicity and safety of booster immunization of varicella live attenuated vaccine (varicella vaccine hereafter) at different intervals.


Eligibility criteria: Inclusion Criteria:

* Healthy children aged 7-12 years;
* Has previously received a single dose of varicella vaccine, with at least 3 months since the first dose;
* The subject or legal guardian can understand and sign the informed consent form (double signature is required for those over 8 years old);
* Participants and their legal guardians voluntarily participate in the study and are able to comply with all study procedures;
* Provide legal identity proof;

Exclusion Criteria:

* History of varicella;
* History of severe allergic reactions to vaccines (such as acute anaphylaxis, angioedema, dyspnea, etc.);
* Suffering from acute disease, severe chronic disease, acute exacerbation of chronic disease;
* With any confirmed or suspected immunodeficiency disease, immunocompromised or receiving immunosuppressive therapy (including systemic steroid therapy);
* With a history of congenital immune diseases or close contact with family members with a history of congenital immune diseases;
* With encephalopathy, uncontrolled epilepsy, other progressive neurological disorders, history of Guillain-Barre syndrome;
* Body temperature \>37℃ at the time of vaccination;
* Receipt of blood products within 3 months before receiving investigational vaccine;
* Receipt of another study drug within 30 days before receipt of the investigational vaccine;
* Receipt of live attenuated vaccine within 28 days before receipt of investigational vaccine;
* Receipt of subunit or inactivated vaccine within 7 days before receipt of investigational vaccine;
* Participated in other clinical trials before enrollment and were enrolled in another clinical trial during the follow-up period or planned to participate in another clinical trial within 3 months;
* The participant had any other factors that were ineligible for vaccination by in the investigator's judgment.

Primary outcomes:
measure: Geometric mean titer (GMT) of varicella-zoster virus (VZV) antibodies
timeFrame: 30 days after booster dose immunization
Secondary outcomes:
measure: Seroconversion rate of varicella-zoster virus (VZV) antibodies
timeFrame: 30 days after booster dose immunization
measure: Seropositive rate of varicella-zoster virus (VZV) antibodies
timeFrame: 30 days after booster dose immunization
measure: Geometric mean increase (GMI) of varicella-zoster virus (VZV) antibodies
timeFrame: 30 days after booster dose immunization
Other outcomes:
Locations:
city: Nanjing
country: China
facility: Jiangsu Provincial Center for Disease control and Prevention
state: Jiangsu
Study officials:
References: