Varicella (Chickenpox)Phase 3NCT07415252
SkyVaricella® (NBP608) Vaccine With Lower Potencies in Healthy Children Aged 12 Months to 12 Years
A Phase 3 study testing NBP608 (Mid Potency), NBP608 (Low Potency) and Varivax® in people with Varicella (Chickenpox), run by SK Bioscience Co., Ltd. at 14 sites in 4 countries.
Trial summary
The goal of this study is to evaluate the safety and immunogenicity of an investigational varicella vaccine in children. Researchers will compare the investigational vaccine, NBP608, with licensed varicella vaccines. The study includes children aged 12 months to 12 years. Read more about this study
- Who is it for?
- Ages 12 months to 12 yearsHealthy volunteers can take part
- Conditions the study is for
- Varicella (Chickenpox)
- What is being tested?
- NBP608 (Mid Potency), NBP608 (Low Potency) and Varivax®
- Type of treatment
- Vaccines, Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 780 participants
- Where
- 14 sitesin 4 countries
- Study dates
- 4 Jul 2026to 2 Jan 2028
- 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 12 months to 12 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Participant must be ≥12 months to ≤12 years of age, at the time of informed consent.
- Participant is healthy or medically stable, as determined by the investigator through medical history, physical examination, and overall clinical assessment.
- Participant's parents/LARs are able and willing to comply with all study procedures and attend all scheduled visits.
- Female participants of childbearing potential must agree to comply with applicable contraceptive requirements as defined in the protocol.
- Female participants of a childbearing potential must have a negative urine pregnancy test at screening; pregnancy testing is not required for those not of childbearing potential.
- Participant's parents/LARs are capable of providing signed informed consent, including agreement to comply with the requirements and restrictions specified in this protocol and in the informed consent form (ICF), before initiation of any study-specific procedures. Where applicable, the participant must also be able to provide written assent in accordance with local regulations and IRB/IEC requirements.
Who cannot join
- 1. Participants with any acute illness, including fever or clinically significant symptoms, at the time of study vaccination. 2. History of varicella-zoster virus (VZV) infection or recent exposure to VZV.
- 3. Presence of household contacts at high risk for severe VZV infection 4. History of immunodeficiency, autoimmune disease, or other conditions affecting the immune system.
- 5. History of bleeding disorders contraindicating vaccination. 6. History of severe allergic reactions to vaccines or vaccine components. 7. History of Guillain-Barré syndrome associated with prior vaccination. 8. Active untreated tuberculosis infection. 9. Any significant medical condition that, in the investigator's judgment, may interfere with study participation or interpretation of results.
- 10. Prior receipt of any varicella-containing vaccine. 11. Receipt or planned use of vaccines, medications, immunoglobulins, blood products, or immunosuppressive therapies that may interfere with study evaluation, as defined in the protocol.
- 12. Participation in another clinical study involving an investigational intervention within a protocol-defined timeframe.
- 13. Study staff, investigators, and their immediate family members.
Trial locations and contacts
14 sites in 4 countries. Contact the study team or a site near you to ask about taking part.
14 sites in 4 countries
South Korea8 sites, 8 recruiting
- Recruiting
Ansan, site 401
Ansan, Gyeonggi-do, 15355
- Recruiting
Daegu, site 404
Daegu, Daegu, 42601
- Not yet recruiting
Hwaseong-si, site 406
Hwaseong-si, Gyeonggi-do, 18450
- Recruiting
Incheon, site 403
Incheon, Incheon, 21431
- Not yet recruiting
Seongnam-sit, site 405
Seongnam-si, Gyeonggi-do, 13620
- Recruiting
Seoul, site 402
Seoul, Seoul, 02841
- Not yet recruiting
Seoul, site 408
Seoul, Seoul, 07985
- Not yet recruiting
Seoul, site 407
Seoul, Seoul, 08308
Philippines3 sites, 3 recruiting
- Recruiting
Manila, site 301
Manila, National Capital Region, 1000
- Recruiting
Quezon City, site 302
Quezon City, National Capital Region, 1113
- Recruiting
Quezon City, site 303
Quezon City, National Capital Region, 1118
Honduras2 sites, 2 recruiting
- Not yet recruiting
San Pedro Sula, site 101
San Pedro Sula, Cortés Department, 21104
- Recruiting
Tegucigalpa, site 102
Tegucigalpa, Francisco Morazán Department, 11101
Thailand1 site, 1 recruiting
- Not yet recruiting
Khon Kaen City, site 201
Khon Kaen, Changwat Khon Kaen, 40002
About this study
Official title: A Phase III, Randomized, Double-blinded, Active-controlled, Multinational, Multicenter Study to Assess the Safety and Immunogenicity of a Two-dose Regimen of SKYVaricella® (NBP608) in Children Aged 12 Months to 12 Years
The goal of this study is to evaluate the safety and immunogenicity of an investigational varicella vaccine in children. Researchers will compare the investigational vaccine, NBP608, with licensed varicella vaccines. The study includes children aged 12 months to 12 years.
Participants will be randomly assigned to receive either the investigational vaccine (NBP608) or licensed varicella vaccines.
Participants will:
Receive two subcutaneous injections of a study vaccine administered. Visit the study clinic seven times over approximately 15 months. Receive follow-up phone calls 7 days after each vaccination to monitor for safety.
Read the detailed description
This is a Phase III, randomized, Double-blinded, Active-controlled, Multinational, Multicenter study designed to evaluate the safety and immunogenicity of a two-dose regimen of NBP608 in children aged 12 months to 12 years.
Immunogenicity will be assessed using blood samples collected at predefined time points to evaluate immune responses to varicella.
Safety will be evaluated throughout the study by monitoring adverse events (AEs), serious adverse events (SAEs), and adverse events of special interest (AESIs) following vaccination.
Each participant will take part in the study for approximately 15 months, including scheduled clinic visits and follow-up assessments.
- Conditions
- Varicella (Chickenpox)
- Being tested
- NBP608 (Mid Potency), NBP608 (Low Potency), Varivax®, SKYVaricella®, Normal Saline (Placebo)
- Keywords
- SKYVaricella, NBP608, Varicella vaccine, Chickenpox vaccine, Pediatric vaccination
- Medical subject headings
- Chickenpox
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
NBP608 (Mid Potency)Biological
NBP608 (mid potency) is a live attenuated varicella virus vaccine (Oka/SK strain).
NBP608 (Low Potency)Biological
NBP608 (low potency) is a live attenuated varicella virus vaccine (Oka/SK strain).
Varivax®Biological
Varivax® is a licensed live attenuated varicella virus vaccine (Oka/Merck strain).
SKYVaricella®Biological
SKYVaricella® is a licensed live attenuated varicella virus vaccine (Oka/SK strain).
Normal Saline (Placebo)Other
Placebo consisting of normal saline (0.9% sodium chloride solution).
| Study group | Role | What they receive |
|---|---|---|
| Test group 1: NBP608 (Mid Potency) | Experimental | Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. Receives: Biological: NBP608 (Mid Potency); Other: Normal Saline (Placebo) |
| Test group 2: NBP608 (Low Potency) | Experimental | Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. Receives: Biological: NBP608 (Low Potency); Other: Normal Saline (Placebo) |
| Active control group 1: Varivax® | Experimental | Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. Receives: Biological: Varivax®; Other: Normal Saline (Placebo) |
| Active control group 2: SKYVaricella® | Experimental | Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. Receives: Biological: SKYVaricella®; Other: Normal Saline (Placebo) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Seroconversion rate of varicella-zoster virus(VZV)
Seroconversion rate of varicella-zoster virus(VZV) IgG antibodies at 6 weeks after each vaccination
Measured: 6 weeks after each dose.
Geometric mean antibody titer (GMT) of varicella-zoster virus(VZV) IgG antibodies
Geometric mean antibody titer (GMT) of varicella-zoster virus(VZV) IgG antibodies at 6 weeks after the second vaccination
Measured: 6 weeks after the second dose.
Secondary outcomes (9)
Seroconversion Rates
Proportion of participants who are seronegative prior to vaccination at each specified assessment time point.
Measured: Time Frame: 6 weeks after each vaccination, 6 months after the second vaccination
Geometric Mean Titers (GMTs)
VZV IgG antibodies at each specified time point.
Measured: 6 weeks after each vaccination, 6 months after the second vaccination
Geometric Mean Fold Rise (GMFR)
Fold increases in VZV IgG antibody titers
Measured: from baseline to each post-vaccination timepoint
Geometric Mean Fold Reduction (GMFRd)
Fold reductions in VZV IgG antibody titers
Measured: from baseline to each post-vaccination timepoint
Immediate reactions
Percentage of participants reporting any immediate reactions following each vaccination.
Measured: Within 30 minutes
Solicited adverse events
Percentage of participants reporting solicited adverse events following each vaccination.
Measured: Within 14 days
Unsolicited adverse events
Percentage of participants experiencing any unsolicited adverse events following each vaccination.
Measured: Within 42 days
Serious adverse events, medically attended AEs, and AEs leading to withdrawal
Percentage of participants experiencing any serious adverse events, medically attended adverse events, or adverse events leading to withdrawal during the study period.
Measured: during study period
Adverse events of special interest
Percentage of participants experiencing any adverse events of special interest during the study period.
Measured: during the study period
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Feb 2026
- Study start4 Jul 2026
- Primary completion13 Feb 2027 (estimated)
- Study completion2 Jan 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Varicella (Chickenpox)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 780 participants (estimated)
Sponsor and investigators
- Lead sponsor
- SK Bioscience Co., Ltd.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07415252
- Sponsor's protocol ID
- NBP608_004
- Status last verified
- Sep 2026
- First submitted
- 27 Jan 2026
- Last updated
- 15 Sep 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase III, Randomized, Double-blinded, Active-controlled, Multinational, Multicenter Study to Assess the Safety and Immunogenicity of a Two-dose Regimen of SKYVaricella® (NBP608) in Children Aged 12 Months to 12 Years
- ClinicalTrials.gov ID
- NCT07415252
- Acronym / sponsor ID
- NBP608_004
- Conditions
- Varicella (Chickenpox)
- Keywords
- SKYVaricella, NBP608, Varicella vaccine, Chickenpox vaccine, Pediatric vaccination
- Phase
- Phase 3
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 780 participants (estimated)
- Lead sponsor
- SK Bioscience Co., Ltd.Industry (pharma, biotech, devices)
- Study start
- 4 Jul 2026 (actual)
- Primary completion
- 13 Feb 2027 (estimated)
- Study completion
- 2 Jan 2028 (estimated)
- First posted
- 17 Feb 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this study is to evaluate the safety and immunogenicity of an investigational varicella vaccine in children. Researchers will compare the investigational vaccine, NBP608, with licensed varicella vaccines. The study includes children aged 12 months to 12 years.
Participants will be randomly assigned to receive either the investigational vaccine (NBP608) or licensed varicella vaccines.
Participants will:
Receive two subcutaneous injections of a study vaccine administered. Visit the study clinic seven times over approximately 15 months. Receive follow-up phone calls 7 days after each vaccination to monitor for safety.
Detailed description
This is a Phase III, randomized, Double-blinded, Active-controlled, Multinational, Multicenter study designed to evaluate the safety and immunogenicity of a two-dose regimen of NBP608 in children aged 12 months to 12 years.
Immunogenicity will be assessed using blood samples collected at predefined time points to evaluate immune responses to varicella.
Safety will be evaluated throughout the study by monitoring adverse events (AEs), serious adverse events (SAEs), and adverse events of special interest (AESIs) following vaccination.
Each participant will take part in the study for approximately 15 months, including scheduled clinic visits and follow-up assessments.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Test group 1: NBP608 (Mid Potency) | Experimental | Biological: NBP608 (Mid Potency), Other: Normal Saline (Placebo)Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. |
| Test group 2: NBP608 (Low Potency) | Experimental | Biological: NBP608 (Low Potency), Other: Normal Saline (Placebo)Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. |
| Active control group 1: Varivax® | Experimental | Biological: Varivax®, Other: Normal Saline (Placebo)Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. |
| Active control group 2: SKYVaricella® | Experimental | Biological: SKYVaricella®, Other: Normal Saline (Placebo)Participants receive either a one-dose regimen or a two-dose regimen consisting of two subcutaneous injections administered. |
Who may qualify
- Ages
- 12 months to 12 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (6 listed)
- Participant must be ≥12 months to ≤12 years of age, at the time of informed consent.
- Participant is healthy or medically stable, as determined by the investigator through medical history, physical examination, and overall clinical assessment.
- Participant's parents/LARs are able and willing to comply with all study procedures and attend all scheduled visits.
- Female participants of childbearing potential must agree to comply with applicable contraceptive requirements as defined in the protocol.
- Female participants of a childbearing potential must have a negative urine pregnancy test at screening; pregnancy testing is not required for those not of childbearing potential.
Key exclusion criteria (6 listed)
- 1. Participants with any acute illness, including fever or clinically significant symptoms, at the time of study vaccination. 2. History of varicella-zoster virus (VZV) infection or recent exposure to VZV.
- 3. Presence of household contacts at high risk for severe VZV infection 4. History of immunodeficiency, autoimmune disease, or other conditions affecting the immune system.
- 5. History of bleeding disorders contraindicating vaccination. 6. History of severe allergic reactions to vaccines or vaccine components. 7. History of Guillain-Barré syndrome associated with prior vaccination. 8. Active untreated tuberculosis infection. 9. Any significant medical condition that, in the investigator's judgment, may interfere with study participation or interpretation of results.
- 10. Prior receipt of any varicella-containing vaccine. 11. Receipt or planned use of vaccines, medications, immunoglobulins, blood products, or immunosuppressive therapies that may interfere with study evaluation, as defined in the protocol.
- 12. Participation in another clinical study involving an investigational intervention within a protocol-defined timeframe.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| NBP608 (Mid Potency)NBP608 (mid potency) is a live attenuated varicella virus vaccine (Oka/SK strain). | Biological | Test group 1: NBP608 (Mid Potency) |
| NBP608 (Low Potency)NBP608 (low potency) is a live attenuated varicella virus vaccine (Oka/SK strain). | Biological | Test group 2: NBP608 (Low Potency) |
| Varivax®Varivax® is a licensed live attenuated varicella virus vaccine (Oka/Merck strain). | Biological | Active control group 1: Varivax® |
| SKYVaricella®SKYVaricella® is a licensed live attenuated varicella virus vaccine (Oka/SK strain). | Biological | Active control group 2: SKYVaricella® |
| Normal Saline (Placebo)Placebo consisting of normal saline (0.9% sodium chloride solution). | Other | Active control group 1: Varivax®, Active control group 2: SKYVaricella®, Test group 1: NBP608 (Mid Potency), Test group 2: NBP608 (Low Potency) |
Primary outcome
Seroconversion rate of varicella-zoster virus(VZV)
Time frame: 6 weeks after each dose.
Seroconversion rate of varicella-zoster virus(VZV) IgG antibodies at 6 weeks after each vaccination
Geometric mean antibody titer (GMT) of varicella-zoster virus(VZV) IgG antibodies
Time frame: 6 weeks after the second dose.
Geometric mean antibody titer (GMT) of varicella-zoster virus(VZV) IgG antibodies at 6 weeks after the second vaccination
9 secondary outcomes
Seroconversion Rates
Time frame: Time Frame: 6 weeks after each vaccination, 6 months after the second vaccination
Geometric Mean Titers (GMTs)
Time frame: 6 weeks after each vaccination, 6 months after the second vaccination
Geometric Mean Fold Rise (GMFR)
Time frame: from baseline to each post-vaccination timepoint
Geometric Mean Fold Reduction (GMFRd)
Time frame: from baseline to each post-vaccination timepoint
Immediate reactions
Time frame: Within 30 minutes
Solicited adverse events
Time frame: Within 14 days
Unsolicited adverse events
Time frame: Within 42 days
Serious adverse events, medically attended AEs, and AEs leading to withdrawal
Time frame: during study period
Adverse events of special interest
Time frame: during the study period
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
14 sites in 4 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 3 study testing NBP608 (Mid Potency), NBP608 (Low Potency) and Varivax® in people with Varicella (Chickenpox), run by SK Bioscience Co., Ltd. at 14 sites in 4 countries.
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 6 inclusion and 6 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 15 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 14 sites in South Korea, Philippines, Honduras, Thailand. 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?
Contact Bora Kim (82-2-2008-2200, bora.kim@sk.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Seroconversion rate of varicella-zoster virus(VZV) (time frame: 6 weeks after each dose.). 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?
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 15 Sep 2026; AzTrials last refreshed its copy on 8 Nov 2026.