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Varicella (Chickenpox)Phase 3NCT07475000

Second Dose of Varicella Vaccine in Healthy Children

A Phase 3 study testing PROVARIX in people with Varicella (Chickenpox) and Varicella Immunisation, run by Sinovac (Dalian) Vaccine Technology Co., Ltd. at 5 sites in Turkey (Türkiye).

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

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. Read more about this study

Who is it for?
Ages 15 months to 12 yearsHealthy volunteers can take part
What is being tested?
PROVARIX
Type of treatment
Vaccines
Could I receive a placebo?
No, everyone receives an active treatment
How many people
300 participants
Where
5 sitesTurkey (Türkiye)
Study dates
28 Jan 2026to 15 Nov 2026
Phase
Phase 3
Are there results?
Not yet: the study is under way

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 15 months to 12 years
  • All sexes
  • Healthy volunteers accepted
  • Child

Who may be able to join

  • 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.

Who cannot join

  • 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).
Show all 16Show fewer
  • 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.

Trial locations and contacts

5 sites in 1 country. Contact the study team or a site near you to ask about taking part.

5 sites in 1 country

Turkey (Türkiye)5 sites, 5 recruiting

  • Akdeniz University Health, Research and Application Center (Hospital), Department of Child Health and Diseases, Department of Social Pediatrics

    Akdeniz

    Assoc. Prof. Dr. Tuğçe TURAL KARA, tugceturalkara@gmail.com

    Recruiting

  • Ankara Bilkent City Hospital, Pediatrics and Pediatric Infectious Diseases Clinic

    Ankara

    Prof. Betül ULUKOL, betul.ulukol@gmail.com

    Not yet recruiting

  • Hacettepe University Hospitals, Department of Pediatrics, Department of Social Pediatrics

    Ankara

    Prof. Sıdıka Songül YALÇIN, siyalcin@hacettepe.edu.tr

    Recruiting

  • REPUBLIC of TURKEY MINISTRY of HEALTH ANKARA BILKENT CITY HOSPITAL

    Ankara

    Prof. Aslı Nur Özkaya Parlakay, MD, ankarash.etikkurul2@saglikgov.tr

    Not yet recruiting

  • Ege University Hospital (Application and Research Center) Department of Child Health and Diseases

    Ege

    Prof. Feyza KOÇ, feyzaumaykoc@yahoo.com

    Not yet recruiting

Other trials in Turkey (Türkiye)

About this study

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

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.

Being tested
PROVARIX
Medical subject headings
Chickenpox

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • PROVARIXBiological

    Participants will receive one dose (0.5 mL) of PROVARIX (VarV), a live attenuated varicella vaccine manufactured by Sinovac (Dalian) Vaccine Technology Co., Ltd., administered as the second dose of varicella vaccination.

Study groups in NCT07475000
Study groupRoleWhat they receive
Group 1ExperimentalThe first dose administered was VARIVAX(varicella vaccine manufactured by Merck)
Receives: Biological: PROVARIX
Group 2ExperimentalThe first dose administered was VARILRIX(varicella vaccine manufactured by GSK)
Receives: Biological: PROVARIX
Group 3ExperimentalThe first dose administered was SUDUVAX(varicella vaccine manufactured by GC Biopharma)
Receives: Biological: PROVARIX
Group 4ExperimentalThe first dose administered was SKYVaricella(varicella vaccine manufactured by SK bioscience)
Receives: Biological: PROVARIX
Group 5ExperimentalThe first dose administered was PROVARIX(varicella vaccine manufactured by Sinovac)
Receives: Biological: PROVARIX

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Geometric Mean Concentration (GMC) of Varicella-Zoster Virus (VZV) Antibodies

    Measured: 42 days after vaccination (Day 42)

  2. Geometric Mean Fold Rise (GMFR) of Varicella-Zoster Virus (VZV) Antibodies

    Measured: 42 days after vaccination (Day 42)

Secondary outcomes (4)

  1. Seropositive Rate of Varicella-Zoster Virus (VZV) Antibodies

    Measured: 42 days after vaccination (Day 42)

  2. Seroresponse Rate of Varicella-Zoster Virus (VZV) Antibodies

    Measured: 42 days after vaccination (Day 42)

  3. Incidence of Adverse Reactions Within 42 Days After Vaccination

    Measured: Day 0 to Day 42 after vaccination

  4. Incidence of Serious Adverse Events (SAEs)

    Measured: Day 0 to Day 180 after vaccination

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted16 Mar 2026
  2. Study start28 Jan 2026
  3. Primary completion15 Jul 2026 (estimated)
  4. Study completion15 Nov 2026 (estimated)

Resources

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 3
Primary purpose
Prevention
Allocation
Non-randomised
Intervention model
Parallel groups
Masking
None (open label)
Enrolment
300 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07475000
Sponsor's protocol ID
PRO-VZV-4010
Status last verified
Mar 2026
First submitted
11 Feb 2026
Last updated
16 Mar 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing PROVARIX in people with Varicella (Chickenpox) and Varicella Immunisation, run by Sinovac (Dalian) Vaccine Technology Co., Ltd. at 5 sites in Turkey (Türkiye).

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 5 inclusion and 16 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: looking for participants now, as of the sponsor's last update on 16 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 5 sites in Turkey (Türkiye). 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 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Geometric Mean Concentration (GMC) of Varicella-Zoster Virus (VZV) Antibodies (time frame: 42 days after vaccination (Day 42)). 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?

On the ClinicalTrials.gov record for NCT07475000.

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 16 Mar 2026.

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