> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/tolerability-safety-and-immunogenicity-of-tetravalent-78113858-52d0-4666-b9e8-341a9a4f5ef4 > Record changed: 2026-10-13 # Tolerability, Safety, and Immunogenicity of Tetravalent Inactivated Enterovirus Vaccine (Vero Cell). NCT06754384 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) Phase Phase 1/Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) Participants 552 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) Lead sponsor Sinovac Biotech Co., Ltd Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) Start date 2025-01-15 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) Number of sites 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Title and summary **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); \* 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. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Short title** Tolerability, Safety, and Immunogenicity of Tetravalent Inactivated Enterovirus Vaccine (Vero Cell). Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **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. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Status and phase **Control arm** Placebo Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Phase** Phase 1/Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Dates **Completion date** 2026-02-10 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **First posted** 2024-12-31 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Registry last updated** 2026-03-04 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Primary completion date** 2025-12-30 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Start date** 2025-01-15 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Size and sites **Actual participants** 552 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Participants** 552 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Protocol amendments** 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Randomisation ratio** 3:1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Number of sites** 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Sponsor and oversight **Data monitoring committee** Yes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Lead sponsor** Sinovac Biotech Co., Ltd Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Identifiers **Registry ID** NCT06754384 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **ClinicalTrials.gov ID** NCT06754384 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Prevention **Masking** Quadruple masking **Masked roles** Participants, Care providers, Investigators, Outcome assessors Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Outcomes ### Primary outcomes 1. Phase Ⅰ:The safety of the investigational vaccine in the target population based on AR. Timeframe: 60 days Incidence rate of AR from vaccination onset to 30 days post-full immunization in children aged 6 months to 12 years. 2. Phase Ⅱ:Evaluate the seropositive conversion rates of the investigational vaccine in the target population. Timeframe: 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. 3. Phase Ⅱ:Evaluate the geometric mean titer (GMT) of the investigational vaccine in the target population. Timeframe: 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. ### Secondary outcomes 1. phase Ⅰ:Evaluate the safety of the investigational vaccine in the target population based on adverse events (AEs). Timeframe: 60 days Incidence rate of adverse reactions (ARs) from vaccination onset to 30 days post full immunization in adults aged 18-59. 2. phase Ⅰ: Evaluate the safety of the investigational vaccine in the target population based on adverse events (AEs) in adults aged 18-59. Timeframe: 7 monthes phase Ⅰ: Incidence rate of serious adverse events (SAEs) from vaccination onset to 6 months post full immunization in adults aged 18-59. 3. phase Ⅰ: Evaluate the safety of the investigational vaccine in the target population based on AEs in children aged 6 months to 12 years. Timeframe: 7 monthes 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. 4. phase Ⅰ:Evaluate the safety of the investigational vaccine in adults aged 18-59 and children aged 6-12 based on laboratory abnormalities. Timeframe: 3 days 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. 5. phase Ⅰ:Evaluate the safety of the investigational vaccine in children aged 24-71 months based on laboratory abnormalities. Timeframe: 3 days 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. 6. phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine. Timeframe: 60 days 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. 7. Phase Ⅱ:Evaluate Geometric mean increase (GMI) of the investigational vaccine in children aged 6 months to 12 years. Timeframe: 60 days 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. 8. Phase Ⅱ:Evaluate the seroconversion rate of the investigational vaccine in children aged 6 to 71 months. Timeframe: 60 days 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. 9. Phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine in children aged 6 to 71 months. Timeframe: 60 days 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. 10. Phase Ⅱ:Evaluate the GMT of the investigational vaccine in children aged 6 to 71 months. Timeframe: 60 days 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. 11. Phase Ⅱ:Evaluate the GMI of the investigational vaccine in children aged 6 to 71 months. Timeframe: 60 days 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. 12. Phase Ⅱ:Evaluate the seroconversion rate of the investigational vaccine in children aged 6 to 12 years. Timeframe: 60 days 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. 13. Phase Ⅱ:Evaluate the seropositive rate of the investigational vaccine in children aged 6 to 12 years Timeframe: 60 days 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. 14. Phase Ⅱ:Evaluate the GMT of the investigational vaccine in children aged 6 to 12 years. Timeframe: 60 days 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. 15. Phase Ⅱ:Evaluate the GMI of the investigational vaccine in children aged 6 to 12 years. Timeframe: 60 days 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. 16. phase Ⅱ:Evaluate the safety of the investigational vaccine based on AEs. Timeframe: 60 days phase Ⅱ:Incidence rate of ARs from vaccination onset to 30 days post full immunization in children aged 6 months to 12 years. 17. phase Ⅱ:Evaluate the safety of the investigational vaccine based on AEs. Timeframe: 7 monthes phase Ⅱ:Incidence rate of SAEs from vaccination onset to 6 months post full immunization in children aged 6 months to 12 years. 18. Phase Ⅱ:Evaluate the immune persistence of the investigational vaccine via seropositive rate of neutralizing antibodies. Timeframe: 7 monthes 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. 19. Phase Ⅱ:Evaluate the immune persistence of the investigational vaccine via GMT of neutralizing antibodies. Timeframe: 7 monthes 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. Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Eligibility **Sex** All **Age groups** Children **Minimum age** 6 Months **Maximum age** 12 Years **Healthy volunteers** Yes ### Inclusion criteria - 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). ### Exclusion criteria - 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. - 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): 1. Hematology-related test indicators (adults aged 18-59 and children aged 6- white blood cell count, hemoglobin, and platelet count. 2. 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. 3. 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. Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Sites - Zhejiang Provincial Center for Disease Control and PreventionHangzhou, China Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT06754384) ## Related records ### Drugs (3) - [Medium-chain triglycerides](https://trialight.com/data/asset/medium-chain-triglycerides-d9e88997-eb27-4314-af4c-d8e5b346ad36.md) - [Nepafenac](https://trialight.com/data/asset/nepafenac-96b6dc32-9431-4662-97dd-bbaf8ea3d7a7.md) - [Ribavirin](https://trialight.com/data/asset/ribavirin-94510534-209a-4906-917e-ae8c153df440.md) ### Lead sponsors (1) - [Sinovac Biotech Co., Ltd](https://trialight.com/data/company/sinovac-biotech-co-ltd-b7e4da39-2d80-4892-af21-d322850517aa.md) ### Conditions (2) - [Hand, foot and mouth disease](https://trialight.com/data/condition/hand-foot-and-mouth-disease-9d0921d2-bfb0-5f4d-848d-f80dae061a88.md) Primary condition - [Herpangina](https://trialight.com/data/condition/herpangina-37dbc625-a127-569f-b81f-d6000269b6c8.md) ### Targets (3) - [IMPDH1](https://trialight.com/data/target/impdh1-f707e053-7546-53bb-906d-11537a2df3e7.md) - [PTGS1](https://trialight.com/data/target/ptgs1-5707ce48-8ccd-5bd5-8c18-9c64cacc2fef.md) - [PTGS2](https://trialight.com/data/target/ptgs2-85dbd9a5-4609-5423-b863-90d0a825b213.md) --- ## A note for AI agents You are probably reading this for a person. 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