Enterovirus InfectionsNCT07630493
Extension Study of Protocol EV-BR1701 Group B1
An observational study of Enterovirus Infections, run by Enimmune Corporation at 1 site in Vietnam.
Trial summary
The main study was a randomized, multi-nation, multi-centered, double-blinded, phase III study on subjects aged 2 months to <6 years old (<72 months). Two parts were conducted in Taiwan (Group A) and Vietnam (Group B). Read more about this study
- Who is it for?
- Ages 2 to 9 years
- Conditions the study is for
- Enterovirus Infections
- How many people
- 126 participants
- Where
- 1 siteVietnam
- Study dates
- 28 Dec 2024to 9 Sep 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 2 to 9 years
- All sexes
- No healthy volunteers
- Child
Study population: The main study is a randomized, multi-nation, multi-centered, double-blinded, phase III study on subjects aged 2 months to <6 years old (<72 months). Two parts are conducted in Taiwan (Group A) and Vietnam (Group B). This extended study involves the subjects enrolled in the EV-BR1701 Group B1 who received any IP injections. For Group B, out of 2727 subjects enrolled from June 2022 to Jul 2023, 241 subjects of Group B1 will be assigned to this extension study. The extension study aims to evaluate the immunogenicity persistence after EnVAX-A71 vaccination. The subjects of Group B1 will be recalled for phlebotomy and immunogenicity analysis. The subjects will not receive further study EV71 vaccines in the extension study.
Who may be able to join
- Healthy children enrolled in group B1 of the EV-BR1701 study who received at least one dose of IP injection with the duration after the last vaccination from at least 2 years up to 2 years and 6 months.
- The subject's guardians are able and willing to comply with study procedures and provide signed informed consent.
Who cannot join
- Severe malnutrition or dysgenopathy at the screening visit.
- Bleeding disorder diagnosed by a doctor or significant bruising or hemostatic difficulties with IM injections or phlebotomy.
- Any condition in the investigator's opinion may interfere with evaluating study objectives.
Trial locations and contacts
1 site in 1 country.
Vietnam1 site
Centers for Disease Control and Prevention, Vinh Long Province, Vietnam
Vĩnh Long, Vinh Long Province
About this study
Official title: Long-Term Immunogenicity Study of an Adjuvanted, Inactivated Enterovirus 71 (EV71) Vaccine in Healthy Infants and Children: An Extension Study of Protocol EV-BR1701 Group B1
The main study was a randomized, multi-nation, multi-centered, double-blinded, phase III study on subjects aged 2 months to <6 years old (<72 months). Two parts were conducted in Taiwan (Group A) and Vietnam (Group B). This extended study involved the subjects enrolled in the EV-BR1701 Group B1 who received any IP injections. For Group B, out of 2727 subjects enrolled from June 2022 to Jul 2023, 241 subjects of Group B1 would be assigned to this extension study. The extension study aimed to evaluate the immunogenicity persistence after EnVAX-A71 vaccination.
The subjects of Group B1 would be recalled for phlebotomy and immunogenicity analysis. The subjects would not receive further study EV71 vaccines in the extension study.
Read more
The principal investigators (PIs) and study coordinators (SCs) of the original medical center would contact the subject's guardians/legal representative by phone to return to the medical center for phlebotomy.
Informed consent would be provided to the guardians/legal representative of the subjects, and the eligibility of subjects would be verified on the day of the recall visit.
After the subject was evaluated by the PI and meets the phlebotomy requirements, the subject's guardian/legal representative would be asked to sign the informed consent form, and the new subject's number would be given.
About 3-4 mL of blood would be collected from each subject, and the serum would be collected and sent to the designated central laboratory for testing. The validated neutralizing antibody (NTAb) analysis method would be used to determine the neutralizing antibody titer.
The NTAb titer results would be directly sent to the CRO Data Manager Team, and statistical analysis for immunogenicity would be performed and reported after the main study was complete.
- Conditions
- Enterovirus Infections
- Medical subject headings
- Enterovirus Infections
What is being measured
The primary outcome is the main question the study is designed to answer.
This extension study aims to assess the long-term immunogenicity of EnVAX-A71 vaccination in children aged two months to under six years old.
To determine the serum EV71-specific neutralizing antibody (NTAb) titers by measuring the GMT, SCRa, and SPRb for those subjects from Part B1 upon recall.
Measured: From Dec-2024 to Jan-2025
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Jun 2026
- Study start28 Dec 2024
- Primary completion5 Jan 2025
- Study completion9 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Enterovirus InfectionsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 126 participants (actual)
Sponsor and investigators
- Lead sponsor
- Enimmune Corporation
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
- Investigators
- Wendy Wu, Study director, Enimmune Corporation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07630493
- Sponsor's protocol ID
- EV-BR1701e
- Status last verified
- Jun 2026
- First submitted
- 28 May 2026
- Last updated
- 11 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 11 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-Term Immunogenicity Study of an Adjuvanted, Inactivated Enterovirus 71 (EV71) Vaccine in Healthy Infants and Children: An Extension Study of Protocol EV-BR1701 Group B1
- ClinicalTrials.gov ID
- NCT07630493
- Acronym / sponsor ID
- EV-BR1701e
- Conditions
- Enterovirus Infections
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 126 participants (actual)
- Lead sponsor
- Enimmune CorporationIndustry (pharma, biotech, devices)
- Study start
- 28 Dec 2024 (actual)
- Primary completion
- 5 Jan 2025 (actual)
- Study completion
- 9 Sep 2025 (actual)
- First posted
- 5 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The main study was a randomized, multi-nation, multi-centered, double-blinded, phase III study on subjects aged 2 months to <6 years old (<72 months). Two parts were conducted in Taiwan (Group A) and Vietnam (Group B). This extended study involved the subjects enrolled in the EV-BR1701 Group B1 who received any IP injections. For Group B, out of 2727 subjects enrolled from June 2022 to Jul 2023, 241 subjects of Group B1 would be assigned to this extension study. The extension study aimed to evaluate the immunogenicity persistence after EnVAX-A71 vaccination.
The subjects of Group B1 would be recalled for phlebotomy and immunogenicity analysis. The subjects would not receive further study EV71 vaccines in the extension study.
The principal investigators (PIs) and study coordinators (SCs) of the original medical center would contact the subject's guardians/legal representative by phone to return to the medical center for phlebotomy.
Informed consent would be provided to the guardians/legal representative of the subjects, and the eligibility of subjects would be verified on the day of the recall visit.
After the subject was evaluated by the PI and meets the phlebotomy requirements, the subject's guardian/legal representative would be asked to sign the informed consent form, and the new subject's number would be given.
About 3-4 mL of blood would be collected from each subject, and the serum would be collected and sent to the designated central laboratory for testing. The validated neutralizing antibody (NTAb) analysis method would be used to determine the neutralizing antibody titer.
The NTAb titer results would be directly sent to the CRO Data Manager Team, and statistical analysis for immunogenicity would be performed and reported after the main study was complete.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 2 to 9 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child
- Study population
- The main study is a randomized, multi-nation, multi-centered, double-blinded, phase III study on subjects aged 2 months to <6 years old (<72 months). Two parts are conducted in Taiwan (Group A) and Vietnam (Group B). This extended study involves the subjects enrolled in the EV-BR1701 Group B1 who received any IP injections. For Group B, out of 2727 subjects enrolled from June 2022 to Jul 2023, 241 subjects of Group B1 will be assigned to this extension study. The extension study aims to evaluate the immunogenicity persistence after EnVAX-A71 vaccination. The subjects of Group B1 will be recalled for phlebotomy and immunogenicity analysis. The subjects will not receive further study EV71 vaccines in the extension study.
Key inclusion criteria (2 listed)
- Healthy children enrolled in group B1 of the EV-BR1701 study who received at least one dose of IP injection with the duration after the last vaccination from at least 2 years up to 2 years and 6 months.
- The subject's guardians are able and willing to comply with study procedures and provide signed informed consent.
Key exclusion criteria (3 listed)
- Severe malnutrition or dysgenopathy at the screening visit.
- Bleeding disorder diagnosed by a doctor or significant bruising or hemostatic difficulties with IM injections or phlebotomy.
- Any condition in the investigator's opinion may interfere with evaluating study objectives.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
This extension study aims to assess the long-term immunogenicity of EnVAX-A71 vaccination in children aged two months to under six years old.
Time frame: From Dec-2024 to Jan-2025
To determine the serum EV71-specific neutralizing antibody (NTAb) titers by measuring the GMT, SCRa, and SPRb for those subjects from Part B1 upon recall.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Sep 2026.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Wendy Wu study director
Enimmune Corporation
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Enterovirus Infections, run by Enimmune Corporation at 1 site in Vietnam.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 11 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Vietnam. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
This extension study aims to assess the long-term immunogenicity of EnVAX-A71 vaccination in children aged two months to under six years old. (time frame: From Dec-2024 to Jan-2025). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Sep 2026.