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A Study to Evaluate the Immunogenicity and Safety of an EV71 Vaccine (Envacgen®) in Children Aged 6 to <10 Years Compared to Children Aged 2 to <6 Years

A Prospective, Open-label, Multi-center, Phase 3 Study to Evaluate the Immunogenicity and Safety of an Inactivated EV71 Enterovirus Vaccine (Envacgen®) in Children Aged 6 to <10 Years Compared to Children Aged 2 to <6 Years

Status
Active, not recruiting
Phases
Phase 3
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07178522
Enrollment
378
Registered
2025-09-17
Start date
2025-06-25
Completion date
2026-10-31
Last updated
2026-05-04

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Enterovirus 71 Inactivated Vaccine

Brief summary

The purpose of this study is to assess the immunogenicity and safety of EV71 vaccine (Envacgen®) in Children Aged 6 to \<10 Years compared to Children Aged 2 to \<6 Years.

Detailed description

This is a prospective, open-label, multi-center, phase 3 study. Participants will receive the first IM injection of study vaccine on Day 1 and will receive a second dose 56 days later. The last study visit is on Day 237 when participants will be contacted via telephone to assess for adverse events .

Interventions

BIOLOGICALEnvacgen®

Subjects are to receive a 0.5 mL IM injection of Envacgen®. Study drug is administered on Day 1 and Day 57 of the study.

Sponsors

Medigen Vaccine Biologics Corp.
Lead SponsorINDUSTRY

Study design

Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
PREVENTION
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
2 Years to 9 Years
Healthy volunteers
Yes

Inclusion criteria

1. Healthy children aged 2 to \<10 years as established by medical history and clinical examination. 2. Subject and/or the subject's parent/guardian is able to understand and sign the ICF.

Exclusion criteria

1. Has poor venous access. 2. Currently has a fever defined as ear/rectal temperature ≥ 38°C or axillary temperature ≥ 37.5 °C within 2 days before the time of planned vaccination. 3. Has had previously known exposure to EV71 or has received EV71 vaccine. 4. Has a history of herpangina or HFMD associated with enterovirus infection in the past 28 days before the date of planned study drug vaccination. 5. Has been diagnosed with a significant neurological, pulmonary, cardiovascular, hematological, hepatic, or renal disorder. 6. Has a history of hypersensitivity to vaccines, or a history of allergic disease or reactions likely to be exacerbated by any component or any residual trace components such as formaldehyde of the Envacgen® vaccine. 7. Has used any investigational/nonregistered product (including drug, vaccine, or invasive medical device) within 28 days before study vaccination or plans to use any of them during the study period. 8. Has confirmed or suspected autoimmune disorder or immunodeficiency. 9. Has been administered or plans to be administered with any licensed live attenuated vaccine within 14 days before or after each study vaccination. 10. Has used immunoglobulins via intravenous route or any blood products within 11 months before vaccination or plans to use any of them during the study period. 11. Has received immunosuppressant, cytotoxic drug, corticosteroid (including prednisolone ≥ 0.5 mg/kg/day or equivalent), immunomodulator or acetylsalicylic acid for \> 14 days within 6 months before the first vaccination or plans to use any of them during the study period. (Inhaled and topical steroids are allowed). 12. Has any medical or psychiatric condition that is a contraindication to protocol participation based on the judgment of the Investigator.

Design outcomes

Primary

MeasureTime frameDescription
Immunogenicity of Envacgen®Day 1 to 28 days after the second vaccination.1. Geometric Mean Titer (GMT) of Neutralizing Antibody (NTAb) Measurement of NTAb titers against EV71 at 28 days after the second dose of Envacgen® in children aged 6 to \<10 years (Old group) compared with children aged 2 to \<6 years (Young group). 2. Seroresponse Rate (SRR) of Neutralizing Antibody (NTAb) Percentage of participants with seroresponse (defined as at least a four-fold increase from baseline in NTAb titers) at 28 days after the second dose of Envacgen® in children aged 6 to \<10 years (Old group) compared with children aged 2 to \<6 years (Young group).
Incidence of Adverse Events(AEs) [Safety]Day 1 to 28 days after the second vaccination.Number and percentage of participants in the Old group (6 to \<10 years) and Young group (2 to \<6 years) with any reported adverse events within 28 days after vaccination with Envacgen®.

Secondary

MeasureTime frameDescription
Incidence of Adverse Events(AEs) [Safety]Day 1 to 180 days after the second vaccination.Number of participants with any adverse events (AEs) reported during the study period.

Countries

Taiwan

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: May 5, 2026