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Not yet recruitingNCT07473427Updated Jun 12, 2026

Immunogenicity and Safety of Varicella Vaccine, Live in Healthy Vietnamese Children

A Phase 3 interventional study of Varicella Vaccine in Varicella (Chickenpox) and Varicella Immunisation, sponsored by Sinovac (Dalian) Vaccine Technology Co., Ltd.. Not yet recruiting at 1 site in Vietnam. Open to participants aged 1 Year to 12 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-12.

Sponsored by Sinovac (Dalian) Vaccine Technology Co., Ltd. (part of Sinovac Biotech Co., Ltd) · Phase 3, Interventional, and Prevention

From the registry’s dates

  • Primary completion was expected by Aug 2026, 3 months ago, but the record still lists the study as not yet recruiting.
Phase
Phase 3
Study type
Interventional
Enrollment
300
Allocation
Non-randomized
Ages
1 Year to 12 Years
Sex
All
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Study summary

This is a single armed, Phase 3 study to assess the immunogenicity and safety of the varicella vaccine manufactured by Sinovac. A total of 300 healthy participants aged 1-12 years will be enrolled. All participants will receive a single dose of varicella vaccine manufactured by Sinovac.

02

Conditions studied

  • Varicella (Chickenpox)
  • Varicella Immunisation

Browse trials for

03

In context

Chickenpox

180 studies on the registry are indexed under Chickenpox; 28 are open to participants now.

This study's planned enrollment of 300 is below the median of 475 across 149 interventional studies indexed under Chickenpox.

Browse Chickenpox studies →

Lead sponsor

Sinovac (Dalian) Vaccine Technology Co., Ltd. is the lead sponsor of 20 studies on the registry; 7 are open to participants now.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
1 Year to 12 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Healthy children aged 1-12 years;
  2. Vaccination history:

    • Participants aged 1 year old: no vaccination history with any varicella containing vaccine;
    • Participants aged 2\~12 years old: no vaccination history with any varicella containing vaccine, or have received 1 dose of varicella vaccine at least 3 months before enrollment;
  3. Participants and/or their legal guardians are able to understand and sign the /assent voluntarily;
  4. Participants are able to comply with the study procedures based on the assessment of the investigator;
  5. Participants should provide verifiable identification, to be contacted, and to contact the investigator during the study period.

Exclusion criteria

Exclusion Criteria:

  1. Prior history of VZV infection;
  2. Have been exposed to VZV at home, day care, school, etc. within 4 weeks before enrollment;
  3. Known allergy to vaccines or vaccine ingredients, or serious adverse reactions to vaccines, such as urticaria, dyspnea, angioneurotic edema;
  4. diseases, immunodeficiency diseases (including but not limited to systemic lupus erythematosus, ankylosing spondylitis, autoimmune thyroid diseases, asplenia, functional asplenia, and infection);
  5. Coagulation disorders (e.g. factor deficiency, disorders), or history of bleeding, hematoma, or bruising following intramuscular injections or venipuncture;
  6. Poorly controlled chronic illnesses or history of severe diseases that, including but not limited to cardiovascular diseases, hematological disorders, liver and kidney diseases, digestive system disorders, respiratory diseases, , and a history of major organ transplantation;
  7. Any confirmed or suspected syphilis, or infection;
  8. Current or history of severe neurological diseases (epilepsy, convulsions or seizures [excluding history of febrile seizures]) or psychiatric disorders, or presence of a family history of psychiatric disorders;
  9. Receipt of ≥14 days of or other immunomodulatory therapy (prednisone ≥20mg/day, or prednisone ≥2mg/kg/day, or its equivalent), cytotoxic therapy within 180 days prior to screening, or plans for such treatment during the trial;
  10. Receipt of blood products or immunoglobulins within 180 days prior to screening, or plans to receive these treatments in the trial;
  11. Receipt of other drugs/vaccines within 30 days prior to screening, or plans to receive such drugs or vaccines during the study period;
  12. Receipt of attenuated or nucleic acid vaccines within 28 days prior to screening, or subunit or inactivated vaccines within 7 days prior to screening;
  13. Fever on vaccination day, with axillary temperature >37.2°C pre-vaccination, or vital signs outside normal range, or failure to pass physical examination;
  14. Presence of skin injuries, inflammation, ulcers, rashes, scars, or other conditions at the intended injection site that may interfere with drug administration or observation of local reactions;
  15. Acute onset of various acute diseases or chronic diseases within the past 7 days, or known or suspected active infections;
  16. Any other factors considered by the investigator to make the participant unsuitable for participation in the trial.
Terms in these criteria, in plain language(10)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

HIV

The human immunodeficiency virus, which weakens the immune system.

Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

Hepatitis B tests

Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.

Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

Immunosuppression

A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.

Read whether the line is about a condition or about medicines, and which medicines and doses it means.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Live vaccines

Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.

05

Study design

Phase
Phase 3
Primary purpose
Prevention
Allocation
Non-randomized
Intervention model
Parallel assignment
Masking
None (open label)
Enrollment
300 participants (estimated)

Study arms

  • Experimental
    No vaccination history group

    Participants aged 1-12 years with no vaccination history of varicella-containing vaccine

    Biological: Varicella Vaccine

  • Experimental
    Vaccination history group

    Participants aged 2-12 years have received 1 dose of varicella vaccine

    Biological: Varicella Vaccine

Interventions

06

What researchers measure

Primary outcomes

  1. The seroresponse rate of varicella-zoster virus (VZV) antibodies among susceptible population without varicella immunization history

    Time frame: 42 days after vaccination

Secondary outcomes

  1. The Geometric Mean Concentration(GMC) of VZV antibodies among susceptible population without varicella immunization history

    Time frame: 42 days after vaccination

  2. The Geometric Mean Concentration(GMC) of VZV antibodies in total population

    Time frame: 42 days after vaccination

  3. The seropositive rate of VZV antibodies in total population

    Time frame: 42 days after vaccination

  4. The geometric mean fold rise (GMFR) of VZV antibodies in total population

    Time frame: 42 days after vaccination

  5. The geometric mean fold rise (GMFR) of VZV antibodies among population with varicella immunization history

    Time frame: 42 days after vaccination

  6. The geometric mean concentration (GMC) of VZV antibodies among population with varicella immunization history

    Time frame: 42 days after vaccination

  7. The seropositive rate of VZV antibodies among population with varicella immunization history

    Time frame: 42 days after vaccination

07

Study locations

1 site
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References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Start is estimated for Jun 2026; primary completion for Aug 2026, 1 month later.

Of 35 industry-sponsored phase 3 interventional studies under Chickenpox, half reached primary completion within 12 months of starting (the median), counting those still running; a quarter within 8 and three quarters within 15. This study's planned 1 month is below that.

Counting every sponsor, half of 39 studies reached it within 13 months; a quarter within 9 and three quarters within 24.

How these figures are worked out, and which studies are left out of them.

Registered
Mar 11, 2026
First posted
Mar 16, 2026
StartEst.
Jun 15, 2026
Primary completionEst.
Aug 1, 2026
CompletionEst.
Oct 1, 2026
Last update
Jun 12, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jun 12, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT07473427
Responsible party
Sponsor
First posted
Mar 16, 2026
Start date
Jun 15, 2026 (estimated)
Primary completion
Aug 1, 2026 (estimated)
Completion
Oct 1, 2026 (estimated)
Last update
Jun 12, 2026

Study contacts

Pham Thi Van Anh
Contact
phamthivananh.hmu@gmail.com
+84- 915 595 690

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.

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Discussion

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Studies of the drug tested here: Chickenpox Vaccine

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