Long-Term Immunogenicity Study of Inactivated EV71 Vaccine in Children

Long-Term Immunogenicity Study of Inactivated EV71 Vaccine Produced in Vero Cells With Adjuvant AlPO4 in Children: Extension Study of Protocol CT-EV-21

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT04072276

Enrollment

227

Registered

2019-08-28

Start date

2019-08-15

Completion date

2021-12-11

Last updated

2022-09-30

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

Conditions

Enterovirus 71 Human

Keywords

EV71 Vaccine

Brief summary

This study is designed to evaluate the long-term antibody titers of EV71 vaccine 4 and 5 years after first dose vaccination for subjects at the age of 2 to \< 6 years , and 3 to 5 years after first dose vaccination for subjects at the age of 2 months to \< 2 years

Detailed description

This is an extension study of protocol CT-EV-21, to evaluate the long-term immunogenicity of EV71vaccine. The first study visit will be approximately 3 or 4 years after the administration of first vaccination of EV71 vaccine or placebo in CT-EV-21 study; 4 years after the first vaccination for subjects 2 to \< 6 years of age (2b), and 3 years after first dose for subjects 2 months to \< 2 years of age (2c and 2d). Subjects of 2b will remain in the study for approximately 12 months and will have 2 clinic visits; subjects of 2c and 2d will remain in the study for approximately 24 months and will have 3 clinic visits. Immunogenicity response against EV71 virus antigen at each visit will be assessed.

Interventions

BIOLOGICALEV71 vaccine

EV71 vaccine with Adjuvant AlPO4 and the placebo (Adjuvant AlPO4 only) were randomly administrated to subject in CT-EV-21 study

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

2 Years to 9 Years

Healthy volunteers

Yes

Inclusion criteria

* Subjects who have completed participation in study CT-EV-21 part 2b, 2c, and 2d, and have received protocol specified doses of EV71 vaccine or Placebo (total of 2 doses in part 2b, and 3 doses for part 2c and 2d). * The subjects' guardians are able to understand and sign the informed consent form.

Exclusion criteria

* Subjects and/or guardians who refuse to comply with the study procedures

Design outcomes

Primary

Measure	Time frame	Description
Serum neutralizing antibody titer	Up to 5 years after first dose of EV71 vaccination	Geometric mean titer (GMT) of EV71 neutralizing antibody titers at 4 and 5 years after first dose of EV71 vaccination for subjects of 2b; and 3 to 5 years after first dose of EV71 vaccination for subjects of 2c and 2d.

Countries

Taiwan

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026