Hand, Foot, and Mouth Disease (HFMD)Phase 1/2NCT06754384
Tolerability, Safety, and Immunogenicity of Tetravalent Inactivated Enterovirus Vaccine (Vero Cell).
A Phase 1/2 study testing Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell), Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell) and High-dose tetravalent inactivated enterovirus vaccine (Vero cell) ) in people with Hand, Foot, and Mouth Disease (HFMD) and Herpangina, run by Sinovac Biotech Co., Ltd at 1 site in China.
Trial summary
The trial aims to assess the tolerability, safety, and immunogenicity of the tetravalent inactivated enterovirus vaccine in adults and children aged 6 months to 12 years. The main questions it aims to answer are: Phase Ⅰ: The safety of the investigational vaccine in the target population based on adverse events (AEs)… Read more about this study
- Who is it for?
- Ages 6 months to 12 yearsHealthy volunteers can take part
- Conditions the study is for
- Hand, Foot, and Mouth Disease (HFMD), Herpangina
- What is being tested?
- Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell), Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell) and High-dose tetravalent inactivated enterovirus vaccine (Vero cell) )
- Type of treatment
- Vaccines
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 552 participants
- Where
- 1 siteChina
- Study dates
- 15 Jan 2025to 10 Feb 2026
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
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 6 months to 12 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Healthy participants aged 18-59 years (only applicable for Phase I) or 6 months to 12 years.
- Participants and/or their legal guardians are able to understand and voluntarily sign the informed consent form (for participants aged 8-12, both the participant and their guardian must sign).
- Willing and able to comply with all visit schedules, sample collection, vaccinations, and other trial procedures, and maintain contact during the trial period.
- Provide identification for the participant and/or their guardian.
- Participants of childbearing participants and their sexual partners must voluntarily use effective contraceptive measures from the time of signing the informed consent form until three months after the completion of the two-dose vaccination series with the investigational vaccine, and have no plans to donate sperm or ova (only applicable for Phase I participants aged 18-59 years).
Who cannot join
- History of HFMD or HA (only applicable to Phase II clinical trial participants).
- Presence of uncontrolled chronic diseases or history of serious illnesses, including but not limited to cardiovascular diseases, hematological diseases, liver and kidney diseases, digestive system diseases, respiratory diseases, malignant tumors, and history of major organ transplantation.
- Severe congenital malformations, genetic defects, or malnutrition.
- Presence of autoimmune diseases or immunodeficiency diseases (including but not limited to systemic lupus erythematosus, ankylosing spondylitis, autoimmune thyroid diseases, asplenia, functional asplenia, HIV infection).
- Abnormal coagulation function (such as coagulation factor deficiency, platelet abnormalities).
- Suffering from/having suffered from severe neurological diseases (epilepsy, convulsions, or seizures [excluding febrile convulsions]), mental illness, or having a family history of mental illness.
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- Acute illnesses or acute exacerbations of chronic illnesses within the past 3 days.
- Having been vaccinated with a vaccine containing any of the components EV71, CA16, CA10, CA6 (including marketed vaccines or investigational vaccines).
- Having received ≥14 days of immunosuppressive or other immunomodulatory treatment (adults: prednisone ≥20mg/day, or children: ≥2mg/kg/day, or equivalent doses; excluding topical or inhaled corticosteroids) within the past 6 months, or cytotoxic treatment, or planning to receive such treatment during the trial.
- Having received immunoglobulins or other blood products within the past 6 months, or planning to receive such treatment during the trial.
- Having received other investigational drugs or vaccines within the past 30 days, or planning to receive such drugs or vaccines during the trial.
- Having received live attenuated vaccines or nucleic acid vaccines within the past 14 days, or subunit or inactivated vaccines within the past 7 days.
- Known allergy to any component of the investigational vaccine (inactivated EV71, CA16, CA10, and CA6 viruses, aluminum hydroxide adjuvant, disodium phosphate, sodium dihydrogen phosphate, sodium chloride, water for injection).
- Participants who are breastfeeding, pregnant, or planning to become pregnant within 3 months after the two doses of vaccination in this trial (only applicable to Phase I).
- On the day of planned vaccination with the investigational vaccine, having an axillary temperature >37.0°C before vaccination, or other vital sign measurements outside the normal range.
- Failing the physical examination on the day of planned vaccination with the investigational vaccine.
- Clinically significant laboratory abnormalities beyond the reference range in clinical laboratory tests (only applicable to Phase I clinical trial participants):
- Hematology-related test indicators (adults aged 18-59 and children aged 6- white blood cell count, hemoglobin, and platelet count.
- Blood chemistry-related test indicators (adults aged 18-59, children aged 6-12, and children aged 24-71 months): alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), fasting blood glucose.
- Urinalysis-related test indicators (adults aged 18-59 and children aged 6-12): urine protein (PRO).
- Presence of skin lesions, inflammation, ulcers, rashes, scars, or other conditions at the intended injection site that may interfere with vaccination or observation of local reactions.
- Any other factors deemed by the investigator to make the participant unsuitable for participation in the clinical trial.
Trial locations and contacts
1 site in 1 country.
China1 site
Zhejiang Provincial Center for Disease Control and Prevention
Hangzhou, Hangzhou
About this study
Official title: Randomized, Double-blind, Controlled Phase I/II Clinical Trial on the Tolerability, Safety, and Immunogenicity of Tetravalent Inactivated Enterovirus Vaccine (Vero Cell) in Healthy Adults and Children Aged 6 Months to 12 Years.
The trial aims to assess the tolerability, safety, and immunogenicity of the tetravalent inactivated enterovirus vaccine in adults and children aged 6 months to 12 years. The main questions it aims to answer are:
- Phase Ⅰ: The safety of the investigational vaccine in the target population based on adverse events (AEs);
- Phase Ⅱ: The immunogenicity of the investigational vaccine in the target population.
Read more
In Phase I, researchers will compare the safety of the investigational vaccine at low, medium, and high doses with the control vaccine; in Phase II, they will compare the safety and immunogenicity (including immune persistence) of the investigational vaccine at medium and high doses with the control vaccine.
Procedure:
- In Phase I, will be vaccinated with the investigational vaccine (at low, medium, and high doses) or the control EV71 vaccine/placebo in a 3:1 ratio, following a vaccination schedule of 0 and 1 month. Within each age group, and under the premise of ensuring safety, a dose-escalation trial will be conducted in reverse order of age.
- In Phase II, participants in each age group will be randomly assigned to the medium-dose, high-dose investigational vaccine groups, and the control group in a 1:1:1 ratio, receiving two doses of the investigational vaccine or the EV71 vaccine (for ages 6-71 months)/placebo (for ages 6-12 years), with a one-month interval between the two doses.
- For all participants in both Phase I and Phase II, immediate reactions within 30 minutes after each dose will be observed. Diary cards/contact cards will be used to collect solicited local and systemic adverse events (AEs) for 0-7 days and unsolicited AEs for 0-30 days after vaccination. Additionally, serious adverse events (SAEs) will be monitored from the start of vaccination until 6 months post-completion of the vaccination schedule. Furthermore, for participants of reproductive age in Phase I, pregnancy events will be collected.
Read the detailed description
Both Phase I and Phase II clinical trials adopt a randomized, double-blind, controlled design.
For Phase I, 192 healthy participants are planned to be enrolled, including 48 adults aged 18-59, 48 children aged 6-12, 48 children aged 24-71 months, and 48 children aged 6-23 months. They will receive two doses of the experimental vaccine or EV71 vaccine (for those aged 6-71 months) / placebo (for those aged 6-12 and 18-59) in the order of low-dose, medium-dose, and high-dose. The interval between the two doses is one month. Enrollment will follow the sequence of adults aged 18-59, children aged 6-12, children aged 24-71 months, and children aged 6-23 months. Within each dosage stage, there will be 16 participants from each age group, and they will receive the experimental vaccine or control EV71 vaccine / placebo in a 3:1 ratio.
The dose escalation principle within each age group is low-dose, medium-dose, and high-dose. Based on the occurrence of AEs and clinical laboratory indicators, the next higher dose stage can only be initiated after a 0-7 day safety observation period following the first dose of the lower dose stage and confirmation of safety. The sequential enrollment principle across age groups is adults aged 18-59, children aged 6-12, children aged 24-71 months, and children aged 6-23 months. For each dose, after completing the 0-7 day safety observation period following the first dose and confirming safety, the next age group can proceed with enrollment for that dose.
For adults aged 18-59 and children aged 6-12, venous blood and urine samples will be collected before each dose and on the 3rd day after vaccination for blood routine tests (about 2.0 ml of venous blood), blood biochemistry tests (about 2.0-3.0 ml of venous blood), and urine routine tests (about 2.0-10.0 ml of urine) to evaluate vaccine safety. For children aged 24-71 months, only about 2.0-3.0 ml of venous blood will be collected at the corresponding time points for blood biochemistry tests.
If more than 10% of participants in each dose stage of the 24-71 month age group experience abnormal laboratory test results related to the investigational vaccine and of clinical significance after the first dose, then for the corresponding dose stage in the 6-23 month age group, blood routine tests (about 1.0 ml of venous blood), blood biochemistry tests (about 2.0-3.0 ml of venous blood), and urine routine tests (about 2.0-10.0 ml of urine) will be conducted on the 3rd day after the first dose, before the second dose, and on the 3rd day after the second dose.
After obtaining safety data for all participants in Phase I for 30 days after the completion of vaccination, the data will be analyzed, and a safety analysis report will be submitted to the Data Monitoring Committee (DMC) and Ethical Committee (EC) for review. Only after confirming safety can the Phase II clinical trial be initiated.
For Phase II, 360 healthy participants aged 6 months to 12 years are planned to be enrolled, including 120 children aged 6-23 months, 120 children aged 24-71 months, and 120 children aged 6-12. Participants in each age group will be randomly assigned to the medium-dose and high-dose groups of the investigational vaccine and the control group in a 1:1:1 ratio, receiving two doses of the investigational vaccine or EV71 vaccine (for those aged 6-71 months) / placebo (for those aged 6-12) with a one-month interval. With the day of the first dose as Day 0, all participants in Phase II will have about 3.0 ml of venous blood collected on Days 0, 60, and 210 to separate serum for EV71, CA16, CA10, and CA6 neutralizing antibody tests, evaluating the vaccine's immunogenicity and immune persistence.
All participants in both Phase I and Phase II will be observed for immediate reactions within 30 minutes after each dose, and solicited local and systemic AEs will be collected for 0-7 days, while unsolicited AEs will be collected for 0-30 days. Additionally, SAE monitoring will be conducted from the start of vaccination until 6 months after the completion of the vaccination schedule. Furthermore, for fertile participants in the Phase I clinical trial, during the trial and after the first dose, pregnancy events of female participants themselves or the partners of male participants will be collected through a combination of active follow-up by researchers and self-reporting by participants.
- Conditions
- Hand, Foot, and Mouth Disease (HFMD), Herpangina
- Being tested
- Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell), Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell), High-dose tetravalent inactivated enterovirus vaccine (Vero cell) ), EV71 inactivated enterovirus vaccine (Vero cell) )(for ages 6-71 months）, placebo (for ages 6-12 years)
- Keywords
- Phase Ⅰ, phase Ⅱ, tolerability, safety, immunogenicity, Hand, Foot, and Mouth Disease (HFMD), Herpangina
- Medical subject headings
- Hand, Foot and Mouth Disease, Herpangina
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell)Biological
Low-dose tetravalent inactivated enterovirus vaccine (Vero cell) )(only for phase Ⅰ）
Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell)Biological
Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell)
High-dose tetravalent inactivated enterovirus vaccine (Vero cell) )Biological
High-dose tetravalent inactivated enterovirus vaccine (Vero cell) )
EV71 inactivated enterovirus vaccine (Vero cell) )(for ages 6-71 months）Biological
EV71 inactivated enterovirus vaccine (Vero cell) )(for ages 6-71 months）
placebo (for ages 6-12 years)Biological
placebo (for ages 6-12 years)
| Study group | Role | What they receive |
|---|---|---|
| Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell) | Experimental | Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell)(Only for phase Ⅰ) Receives: Biological: Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell) |
| Medium-dose of tetravalent inactivated enterovirus vaccine (Vero cell) | Experimental | Medium-dose of tetravalent inactivated enterovirus vaccine (Vero cell) Receives: Biological: Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell) |
| High-dose of tetravalent inactivated enterovirus vaccine (Vero cell) | Experimental | High-dose of tetravalent inactivated enterovirus vaccine (Vero cell) Receives: Biological: High-dose tetravalent inactivated enterovirus vaccine (Vero cell) ) |
| EV71 vaccine | Active comparator | EV71 vaccine (for ages 6-71 months) Receives: Biological: EV71 inactivated enterovirus vaccine (Vero cell) )(for ages 6-71 months） |
| placebo | Placebo comparator | placebo (for ages 6-12 years) Receives: Biological: placebo (for ages 6-12 years) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Phase Ⅰ:The safety of the investigational vaccine in the target population based on AR.
Incidence rate of AR from vaccination onset to 30 days post-full immunization in children aged 6 months to 12 years.
Measured: 60 days
Phase Ⅱ:Evaluate the seropositive conversion rates of the investigational vaccine in the target population.
The seropositive conversion rates of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 months to 12 years.
Measured: 60 days
Phase Ⅱ:Evaluate the geometric mean titer (GMT) of the investigational vaccine in the target population.
The GMT of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 months to 12 years.
Measured: 60 days
Secondary outcomes (19)
phase Ⅰ:Evaluate the safety of the investigational vaccine in the target population based on adverse events (AEs).
Incidence rate of adverse reactions (ARs) from vaccination onset to 30 days post full immunization in adults aged 18-59.
Measured: 60 days
phase Ⅰ: Evaluate the safety of the investigational vaccine in the target population based on adverse events (AEs) in adults aged 18-59.
phase Ⅰ: Incidence rate of serious adverse events (SAEs) from vaccination onset to 6 months post full immunization in adults aged 18-59.
Measured: 7 monthes
phase Ⅰ: Evaluate the safety of the investigational vaccine in the target population based on AEs in children aged 6 months to 12 years.
phase Ⅰ: Incidence rate of serious adverse events (SAEs) from vaccination onset to 6 months post full immunization in children aged 6 months to 12 years.
Measured: 7 monthes
phase Ⅰ:Evaluate the safety of the investigational vaccine in adults aged 18-59 and children aged 6-12 based on laboratory abnormalities.
Incidence rate of clinically significant abnormalities in blood biochemistry, blood routine, and urinalysis indicators on the 3rd day after each dose in adults aged 18-59 and children aged 6-12.
Measured: 3 days
phase Ⅰ:Evaluate the safety of the investigational vaccine in children aged 24-71 months based on laboratory abnormalities.
phase Ⅰ:Incidence rate of clinically significant abnormalities in blood biochemistry indicators on the 3rd day after each dose in children aged 24-71 months.
Measured: 3 days
phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine.
phase Ⅱ: Seropositive rate and of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 months to 12 years.
Measured: 60 days
Phase Ⅱ:Evaluate Geometric mean increase (GMI) of the investigational vaccine in children aged 6 months to 12 years.
Phase Ⅱ: GMI of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 months to 12 years.
Measured: 60 days
Phase Ⅱ:Evaluate the seroconversion rate of the investigational vaccine in children aged 6 to 71 months.
Phase Ⅱ:Seroconversion rate of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 71 months.
Measured: 60 days
Phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine in children aged 6 to 71 months.
Phase Ⅱ:Seropositive rate of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 71 months.
Measured: 60 days
Phase Ⅱ:Evaluate the GMT of the investigational vaccine in children aged 6 to 71 months.
Phase Ⅱ: GMT of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 71 months.
Measured: 60 days
Phase Ⅱ:Evaluate the GMI of the investigational vaccine in children aged 6 to 71 months.
Phase Ⅱ: GMI of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 71 months.
Measured: 60 days
Phase Ⅱ:Evaluate the seroconversion rate of the investigational vaccine in children aged 6 to 12 years.
Phase Ⅱ:Seroconversion rate of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 12 years.
Measured: 60 days
Phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine in children aged 6 to 12 years
Phase Ⅱ:Seropositive rate of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 12 years.
Measured: 60 days
Phase Ⅱ:Evaluate the GMT of the investigational vaccine in children aged 6 to 12 years.
Phase Ⅱ: GMT of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 12 years.
Measured: 60 days
Phase Ⅱ:Evaluate the GMI of the investigational vaccine in children aged 6 to 12 years.
Phase Ⅱ: GMI of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 to 12 years.
Measured: 60 days
phase Ⅱ:Evaluate the safety of the investigational vaccine based on AEs.
phase Ⅱ:Incidence rate of ARs from vaccination onset to 30 days post full immunization in children aged 6 months to 12 years.
Measured: 60 days
phase Ⅱ:Evaluate the safety of the investigational vaccine based on AEs.
phase Ⅱ:Incidence rate of SAEs from vaccination onset to 6 months post full immunization in children aged 6 months to 12 years.
Measured: 7 monthes
Phase Ⅱ:Evaluate the immune persistence of the investigational vaccine via seropositive rate of neutralizing antibodies.
Phase Ⅱ: Seropositive rate of neutralizing antibodies against EV71, CA16, CA10, and CA6 at 6 months post full immunization in children aged 6 months to 12 years.
Measured: 7 monthes
Phase Ⅱ:Evaluate the immune persistence of the investigational vaccine via GMT of neutralizing antibodies.
Phase Ⅱ: GMT of neutralizing antibodies against EV71, CA16, CA10, and CA6 at 6 months post full immunization in children aged 6 months to 12 years.
Measured: 7 monthes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2024
- Study start15 Jan 2025
- Primary completion30 Dec 2025
- Study completion10 Feb 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Hand, Foot, and Mouth Disease (HFMD)Studies of the same condition, open and under way.
- More trials run by Sinovac Biotech Co., LtdThe sponsor's other registered studies.
- 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 1/2
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 552 participants (actual)
Sponsor and investigators
- Lead sponsor
- Sinovac Biotech Co., Ltd
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Wang Shenyu, Dr., Principal investigator, Zhejiang Provincial Center for Disease Control and Prevention
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06754384
- Sponsor's protocol ID
- PRO-QEV-1001
- Status last verified
- Dec 2024
- First submitted
- 22 Dec 2024
- Last updated
- 4 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 4 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Randomized, Double-blind, Controlled Phase I/II Clinical Trial on the Tolerability, Safety, and Immunogenicity of Tetravalent Inactivated Enterovirus Vaccine (Vero Cell) in Healthy Adults and Children Aged 6 Months to 12 Years.
- ClinicalTrials.gov ID
- NCT06754384
- Acronym / sponsor ID
- PRO-QEV-1001
- Conditions
- Hand, Foot, and Mouth Disease (HFMD), Herpangina
- Keywords
- Phase Ⅰ, phase Ⅱ, tolerability, safety, immunogenicity, Hand, Foot, and Mouth Disease (HFMD), Herpangina
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 552 participants (actual)
- Lead sponsor
- Sinovac Biotech Co., LtdIndustry (pharma, biotech, devices)
- Study start
- 15 Jan 2025 (actual)
- Primary completion
- 30 Dec 2025 (actual)
- Study completion
- 10 Feb 2026 (actual)
- First posted
- 31 Dec 2024 (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 trial aims to assess the tolerability, safety, and immunogenicity of the tetravalent inactivated enterovirus vaccine in adults and children aged 6 months to 12 years. The main questions it aims to answer are:
- Phase Ⅰ: The safety of the investigational vaccine in the target population based on adverse events (AEs);
- Phase Ⅱ: The immunogenicity of the investigational vaccine in the target population.
In Phase I, researchers will compare the safety of the investigational vaccine at low, medium, and high doses with the control vaccine; in Phase II, they will compare the safety and immunogenicity (including immune persistence) of the investigational vaccine at medium and high doses with the control vaccine.
Procedure:
- In Phase I, will be vaccinated with the investigational vaccine (at low, medium, and high doses) or the control EV71 vaccine/placebo in a 3:1 ratio, following a vaccination schedule of 0 and 1 month. Within each age group, and under the premise of ensuring safety, a dose-escalation trial will be conducted in reverse order of age.
- In Phase II, participants in each age group will be randomly assigned to the medium-dose, high-dose investigational vaccine groups, and the control group in a 1:1:1 ratio, receiving two doses of the investigational vaccine or the EV71 vaccine (for ages 6-71 months)/placebo (for ages 6-12 years), with a one-month interval between the two doses.
- For all participants in both Phase I and Phase II, immediate reactions within 30 minutes after each dose will be observed. Diary cards/contact cards will be used to collect solicited local and systemic adverse events (AEs) for 0-7 days and unsolicited AEs for 0-30 days after vaccination. Additionally, serious adverse events (SAEs) will be monitored from the start of vaccination until 6 months post-completion of the vaccination schedule. Furthermore, for participants of reproductive age in Phase I, pregnancy events will be collected.
Detailed description
Both Phase I and Phase II clinical trials adopt a randomized, double-blind, controlled design.
For Phase I, 192 healthy participants are planned to be enrolled, including 48 adults aged 18-59, 48 children aged 6-12, 48 children aged 24-71 months, and 48 children aged 6-23 months. They will receive two doses of the experimental vaccine or EV71 vaccine (for those aged 6-71 months) / placebo (for those aged 6-12 and 18-59) in the order of low-dose, medium-dose, and high-dose. The interval between the two doses is one month. Enrollment will follow the sequence of adults aged 18-59, children aged 6-12, children aged 24-71 months, and children aged 6-23 months. Within each dosage stage, there will be 16 participants from each age group, and they will receive the experimental vaccine or control EV71 vaccine / placebo in a 3:1 ratio.
The dose escalation principle within each age group is low-dose, medium-dose, and high-dose. Based on the occurrence of AEs and clinical laboratory indicators, the next higher dose stage can only be initiated after a 0-7 day safety observation period following the first dose of the lower dose stage and confirmation of safety. The sequential enrollment principle across age groups is adults aged 18-59, children aged 6-12, children aged 24-71 months, and children aged 6-23 months. For each dose, after completing the 0-7 day safety observation period following the first dose and confirming safety, the next age group can proceed with enrollment for that dose.
For adults aged 18-59 and children aged 6-12, venous blood and urine samples will be collected before each dose and on the 3rd day after vaccination for blood routine tests (about 2.0 ml of venous blood), blood biochemistry tests (about 2.0-3.0 ml of venous blood), and urine routine tests (about 2.0-10.0 ml of urine) to evaluate vaccine safety. For children aged 24-71 months, only about 2.0-3.0 ml of venous blood will be collected at the corresponding time points for blood biochemistry tests.
If more than 10% of participants in each dose stage of the 24-71 month age group experience abnormal laboratory test results related to the investigational vaccine and of clinical significance after the first dose, then for the corresponding dose stage in the 6-23 month age group, blood routine tests (about 1.0 ml of venous blood), blood biochemistry tests (about 2.0-3.0 ml of venous blood), and urine routine tests (about 2.0-10.0 ml of urine) will be conducted on the 3rd day after the first dose, before the second dose, and on the 3rd day after the second dose.
After obtaining safety data for all participants in Phase I for 30 days after the completion of vaccination, the data will be analyzed, and a safety analysis report will be submitted to the Data Monitoring Committee (DMC) and Ethical Committee (EC) for review. Only after confirming safety can the Phase II clinical trial be initiated.
For Phase II, 360 healthy participants aged 6 months to 12 years are planned to be enrolled, including 120 children aged 6-23 months, 120 children aged 24-71 months, and 120 children aged 6-12. Participants in each age group will be randomly assigned to the medium-dose and high-dose groups of the investigational vaccine and the control group in a 1:1:1 ratio, receiving two doses of the investigational vaccine or EV71 vaccine (for those aged 6-71 months) / placebo (for those aged 6-12) with a one-month interval. With the day of the first dose as Day 0, all participants in Phase II will have about 3.0 ml of venous blood collected on Days 0, 60, and 210 to separate serum for EV71, CA16, CA10, and CA6 neutralizing antibody tests, evaluating the vaccine's immunogenicity and immune persistence.
All participants in both Phase I and Phase II will be observed for immediate reactions within 30 minutes after each dose, and solicited local and systemic AEs will be collected for 0-7 days, while unsolicited AEs will be collected for 0-30 days. Additionally, SAE monitoring will be conducted from the start of vaccination until 6 months after the completion of the vaccination schedule. Furthermore, for fertile participants in the Phase I clinical trial, during the trial and after the first dose, pregnancy events of female participants themselves or the partners of male participants will be collected through a combination of active follow-up by researchers and self-reporting by participants.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 5
| Arm | Type | Receives |
|---|---|---|
| Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell) | Experimental | Biological: Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell)Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell)(Only for phase Ⅰ) |
| Medium-dose of tetravalent inactivated enterovirus vaccine (Vero cell) | Experimental | Biological: Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell)Medium-dose of tetravalent inactivated enterovirus vaccine (Vero cell) |
| High-dose of tetravalent inactivated enterovirus vaccine (Vero cell) | Experimental | Biological: High-dose tetravalent inactivated enterovirus vaccine (Vero cell) )High-dose of tetravalent inactivated enterovirus vaccine (Vero cell) |
| EV71 vaccine | Active comparator | Biological: EV71 inactivated enterovirus vaccine (Vero cell) )(for ages 6-71 months）EV71 vaccine (for ages 6-71 months) |
| placebo | Placebo comparator | Biological: placebo (for ages 6-12 years)placebo (for ages 6-12 years) |
Who may qualify
- Ages
- 6 months to 12 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (5 listed)
- Healthy participants aged 18-59 years (only applicable for Phase I) or 6 months to 12 years.
- Participants and/or their legal guardians are able to understand and voluntarily sign the informed consent form (for participants aged 8-12, both the participant and their guardian must sign).
- Willing and able to comply with all visit schedules, sample collection, vaccinations, and other trial procedures, and maintain contact during the trial period.
- Provide identification for the participant and/or their guardian.
- Participants of childbearing participants and their sexual partners must voluntarily use effective contraceptive measures from the time of signing the informed consent form until three months after the completion of the two-dose vaccination series with the investigational vaccine, and have no plans to donate sperm or ova (only applicable for Phase I participants aged 18-59 years).
Key exclusion criteria (22 listed)
- History of HFMD or HA (only applicable to Phase II clinical trial participants).
- Presence of uncontrolled chronic diseases or history of serious illnesses, including but not limited to cardiovascular diseases, hematological diseases, liver and kidney diseases, digestive system diseases, respiratory diseases, malignant tumors, and history of major organ transplantation.
- Severe congenital malformations, genetic defects, or malnutrition.
- Presence of autoimmune diseases or immunodeficiency diseases (including but not limited to systemic lupus erythematosus, ankylosing spondylitis, autoimmune thyroid diseases, asplenia, functional asplenia, HIV infection).
- Abnormal coagulation function (such as coagulation factor deficiency, platelet abnormalities).
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 |
|---|---|---|
| Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell)Low-dose tetravalent inactivated enterovirus vaccine (Vero cell) )(only for phase Ⅰ） | Biological | Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell) |
| Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell)Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell) | Biological | Medium-dose of tetravalent inactivated enterovirus vaccine (Vero cell) |
| High-dose tetravalent inactivated enterovirus vaccine (Vero cell) )High-dose tetravalent inactivated enterovirus vaccine (Vero cell) ) | Biological | High-dose of tetravalent inactivated enterovirus vaccine (Vero cell) |
| EV71 inactivated enterovirus vaccine (Vero cell) )(for ages 6-71 months）EV71 inactivated enterovirus vaccine (Vero cell) )(for ages 6-71 months） | Biological | EV71 vaccine |
| placebo (for ages 6-12 years)placebo (for ages 6-12 years) | Biological | placebo |
Primary outcome
Phase Ⅰ:The safety of the investigational vaccine in the target population based on AR.
Time frame: 60 days
Incidence rate of AR from vaccination onset to 30 days post-full immunization in children aged 6 months to 12 years.
Phase Ⅱ:Evaluate the seropositive conversion rates of the investigational vaccine in the target population.
Time frame: 60 days
The seropositive conversion rates of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 months to 12 years.
Phase Ⅱ:Evaluate the geometric mean titer (GMT) of the investigational vaccine in the target population.
Time frame: 60 days
The GMT of neutralizing antibodies against EV71, CA16, CA10, and CA6 on the 30th day after full vaccination in children aged 6 months to 12 years.
19 secondary outcomes
phase Ⅰ:Evaluate the safety of the investigational vaccine in the target population based on adverse events (AEs).
Time frame: 60 days
phase Ⅰ: Evaluate the safety of the investigational vaccine in the target population based on adverse events (AEs) in adults aged 18-59.
Time frame: 7 monthes
phase Ⅰ: Evaluate the safety of the investigational vaccine in the target population based on AEs in children aged 6 months to 12 years.
Time frame: 7 monthes
phase Ⅰ:Evaluate the safety of the investigational vaccine in adults aged 18-59 and children aged 6-12 based on laboratory abnormalities.
Time frame: 3 days
phase Ⅰ:Evaluate the safety of the investigational vaccine in children aged 24-71 months based on laboratory abnormalities.
Time frame: 3 days
phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine.
Time frame: 60 days
Phase Ⅱ:Evaluate Geometric mean increase (GMI) of the investigational vaccine in children aged 6 months to 12 years.
Time frame: 60 days
Phase Ⅱ:Evaluate the seroconversion rate of the investigational vaccine in children aged 6 to 71 months.
Time frame: 60 days
Phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine in children aged 6 to 71 months.
Time frame: 60 days
Phase Ⅱ:Evaluate the GMT of the investigational vaccine in children aged 6 to 71 months.
Time frame: 60 days
Phase Ⅱ:Evaluate the GMI of the investigational vaccine in children aged 6 to 71 months.
Time frame: 60 days
Phase Ⅱ:Evaluate the seroconversion rate of the investigational vaccine in children aged 6 to 12 years.
Time frame: 60 days
Phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine in children aged 6 to 12 years
Time frame: 60 days
Phase Ⅱ:Evaluate the GMT of the investigational vaccine in children aged 6 to 12 years.
Time frame: 60 days
Phase Ⅱ:Evaluate the GMI of the investigational vaccine in children aged 6 to 12 years.
Time frame: 60 days
phase Ⅱ:Evaluate the safety of the investigational vaccine based on AEs.
Time frame: 60 days
phase Ⅱ:Evaluate the safety of the investigational vaccine based on AEs.
Time frame: 7 monthes
Phase Ⅱ:Evaluate the immune persistence of the investigational vaccine via seropositive rate of neutralizing antibodies.
Time frame: 7 monthes
Phase Ⅱ:Evaluate the immune persistence of the investigational vaccine via GMT of neutralizing antibodies.
Time frame: 7 monthes
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Mar 2026.
- Individual participant dataSharing planned: Undecided
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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. This study is not recruiting at the moment.
Wang Shenyu, Dr. principal investigator
Zhejiang Provincial Center for Disease Control and Prevention
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Low-dose of tetravalent inactivated enterovirus vaccine (Vero cell), Medium-dose tetravalent inactivated enterovirus vaccine (Vero cell) and High-dose tetravalent inactivated enterovirus vaccine (Vero cell) ) in people with Hand, Foot, and Mouth Disease (HFMD) and Herpangina, run by Sinovac Biotech Co., Ltd at 1 site in China.
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 22 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: finished, as of the sponsor's last update on 4 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 1 site in China. 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. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Phase Ⅰ:The safety of the investigational vaccine in the target population based on AR. (time frame: 60 days). The study lists 3 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 4 Mar 2026.