EV71 Vaccine
Conditions
Brief summary
This trial is designed as a single-center, randomized, double-blind study. A total of 720 infants aged 6 to 35 months are selected (with 240 subjects in each age group: 6-11 months, 12-23 months, and 24-35 months). Subjects from different age groups are randomly allocated to three batch groups in a 1:1:1 ratio, and receive two doses of the EV71 vaccine from the commercial production batch on days 0 and 30. After each vaccination dose, subjects will be observed for immediate reactions for 30 minutes and for solicited adverse events for the next 7 days, as well as for unsolicited adverse events over the 30 days following vaccination. All subjects will have blood samples collected on day 0 (pre-immunization) and day 60 for serum antibody testing. Additionally, 270 subjects will be selected, for additional blood sampling at various time points: 7 days, 14 days, and 30 days after the first dose, and 7 days and 14 days after the second dose, to assess the EV71 antibody levels at different timepoints following various doses of vaccination.
Interventions
BIOLOGICALEV71 Vaccine
EV71 vaccine of commercial production batch
Sponsors
Sinovac Biotech Co., Ltd
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
6 Months to 35 Months
Healthy volunteers
Yes
Inclusion criteria
* Infants and young children aged 6 to 35 months. * Able to provide legal identification. * The guardian of the subject has the ability to understand and agrees to sign the informed consent form.
Exclusion criteria
* Previous vaccination with the EV71 vaccine. * History of hand, foot, and mouth disease. * History of allergies, asthma, including allergies to vaccines or vaccine components, and severe adverse reactions to vaccines, such as urticaria, difficulty breathing, angioedema, or abdominal pain. * Congenital malformations or developmental disorders, genetic defects, severe malnutrition, etc. * Autoimmune diseases or immune deficiencies/immunosuppression. * Severe neurological disorders (epilepsy, convulsions, or seizures) or mental illness. * History of thyroidectomy, asplenia, functional asplenia, or any condition leading to asplenia or splenectomy. * Blood coagulation abnormalities diagnosed by a physician (such as clotting factor deficiencies, coagulopathies, platelet abnormalities) or evident bruising or bleeding disorders. * Treatment with immunosuppressants, cytotoxic therapy, or inhaled corticosteroids within 6 months prior to enrollment (excluding corticosteroid nasal spray therapy for allergic rhinitis, or topical corticosteroid treatment for acute non-complicated dermatitis). * Receipt of blood products within 3 months prior to vaccination with the trial vaccine. * Receipt of other investigational vaccines within 30 days prior to vaccination with the trial vaccine. * Receipt of live attenuated vaccines within 14 days prior to vaccination with the trial vaccine. * Receipt of subunit or inactivated vaccines within 7 days prior to vaccination with the trial vaccine. * Any acute illness or acute exacerbation of chronic illness within the past 7 days. * Fever before receiving the investigational vaccine, with an axillary temperature \> 37.0°C. * Any other factors that, in the investigator's judgment, make the subject unsuitable for participation in the clinical trial.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| The GMT of EV71 neutralizing antibodies 30 days after complete immunization with the EV71 vaccine | 30 days after second dose |
Secondary
| Measure | Time frame |
|---|---|
| Seroconversion rates, seropositive rates, and GMT of antibodies at 7 days, 14 days, and 30 days after the first dose of the EV71 vaccine | 7,14 and 30 days after the first dose |
| Seroconversion rates, seropositive rates, and GMT of antibodies at 7 days and 14 days after the second dose of the EV71 vaccine, as well as the seroconversion rate and seropositive rate at 30 days post-vaccination | 7,14 and 30 days after the second dose |
| The incidence of adverse reactions within 30 days after each dose of the EV71 vaccine | 30 days after each dose |
| The incidence of solicited adverse events within 0-7 days after each dose of the EV71 vaccine | 7 days after each dose |
| The incidence of serious adverse events during the safety observation period | 30 days after the second dose |
Countries
China
Outcome results
None listed