Clinical Trial for Batch Consistency of EV71 Vaccine

NCT07026500 | Completed Phase 4

• 2 other identifiers: PRO-EV71-4009CTR20191800
• Study Type: interventional
• Target: 720
• Locations: 1 country
• Sites: 1

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.

Conditions

EV71 Vaccine

Outcome Measures

Primary Outcomes (1)

• The GMT of EV71 neutralizing antibodies 30 days after complete immunization with the EV71 vaccine

  30 days after second dose

Secondary Outcomes (5)

• 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

Study Arms (3)

Batch group 1

EXPERIMENTAL

EV71 vaccine first commercial production batch

Biological: EV71 Vaccine

Batch group 2

EXPERIMENTAL

EV71 vaccine second commercial production batch

Biological: EV71 Vaccine

Batch group 3

EXPERIMENTAL

EV71 vaccine third commercial production batch

Biological: EV71 Vaccine

Interventions

EV71 Vaccine BIOLOGICAL

EV71 vaccine of commercial production batch

Batch group 1; Batch group 2; Batch group 3

Eligibility Criteria

• Age: 6 Months - 35 Months
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Sinovac Biotech Co., Ltd: lead

Study Sites (1)

Dazhu County Center for Disease Control and Prevention

Dazhu, China

Location

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: INDUSTRY
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 10, 2025
• First Posted: June 18, 2025
• Study Start: September 19, 2019
• Primary Completion: April 30, 2020
• Study Completion: May 31, 2020
• Last Updated: June 18, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

CN (1)