An Extension Study of EV-BR1701 Part A1
Long-Term Immunogenicity Study of an Adjuvanted Inactivated Enterovirus 71 (EV71) Vaccine in Healthy Infants and Children: An Extension Study of EV-BR1701 Part A1
Studieoversikt
Status
Forhold
Detaljert beskrivelse
I. Study Design:
EV-BR1701 was a randomized, multi-nation, multi-centered, double-blinded, phase III study to evaluate the efficacy and safety of an EV71 vaccine, EnVAX-A71, in healthy infants and children in Taiwan (Part A) and Vietnam (Part B). In both Parts, a sub-study for immunogenicity assessment for up to one year was performed. This extension study of EV-BR1701 aims to evaluate the long-term immunogenicity persistence more than 5 years after EnVAX-A71 vaccination in subjects originally participating in the immunogenicity sub-study in Taiwan.
The evaluable subjects of EV-BR1701 Part A1(immunogenicity sub-study), who were aged 2 months to < 6 years when entering the main study and completed two injections of either EnVAX-A71 or placebo with evaluable data for the primary immunogenicity endpoint, will be recalled to enter this extension study for phlebotomy and immunogenicity analysis. These subjects will not receive further vaccination according to this extension study protocol.
The principal investigators (PIs) and study coordinators (SCs) of the original medical center will contact the subject's guardians/legal representative by phone to return to the medical center for phlebotomy. Informed consent will be provided to the guardian/legal representative of the subjects, and the eligibility of subjects will be verified on the day of the recall visit.
After the subject is evaluated by the PI and meets the phlebotomy requirements, the subject's guardian/legal representative will be asked to sign the informed consent form, and the subject will be given the same identifier as what he/she was originally assigned in the main study for continuity of his/her immunogenicity data.
About 3-4 mL of blood will be collected from each subject, and the serum will be collected and sent to the designated central laboratory for testing. The validated neutralizing antibody (NTAb) analysis method will be used to determine the EV71-specific neutralizing antibody titer. The NTAb titer results will be directly sent to the CRO Data Management Team, and statistical analysis for immunogenicity will be performed and reported.
Studietype
Registrering (Faktiske)
Kontakter og plasseringer
Studiesteder
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Hsinchu, Taiwan
- National Taiwan University Hospital HsinChu Branch
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Taichung, Taiwan
- China Medical University Hospital
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Taipei, Taiwan
- National Taiwan University Hospital
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Taoyuan, Taiwan
- Linkou Chang Gung Memorial Hospital
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Deltakelseskriterier
Kvalifikasjonskriterier
Alder som er kvalifisert for studier
- Barn
Tar imot friske frivillige
Prøvetakingsmetode
Studiepopulasjon
Beskrivelse
Inclusion Criteria:
- Healthy children who were enrolled in Part A1 (immunogenicity sub-study) of EV-BR1701, received two injections of either EnVAX-A71 or placebo, and had blood sample collected on Day 56 for primary immunogenicity endpoint analysis (the "evaluable" subjects).
- The subject's guardian/legal representative is able and willing to comply with study procedures and provide signed informed consent.
Exclusion Criteria:
- History of bleeding disorder, hemostatic difficulties or significant bruising caused by phlebotomy since the last visit in EV-BR1701 main study.
- Having been vaccinated with any EV71 vaccine products.
Studieplan
Hvordan er studiet utformet?
Designdetaljer
Hva måler studien?
Primære resultatmål
Resultatmål |
Tiltaksbeskrivelse |
Tidsramme |
|---|---|---|
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The long-term immunogenicity of EnVAX-A71 on the seroconversion rate (SCR)
Tidsramme: From Sep-2025 to Dec-2025
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SCR (seroconversion rate) is defined as the percentage of subjects achieving either a pre-vaccination neutralizing antibody titer <1:8 and a post-vaccination neutralizing antibody titer ≥1:32, OR a pre-vaccination neutralizing antibody titer ≥1:8 and a minimum 4-fold increase in post-vaccination neutralizing antibody titer.
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From Sep-2025 to Dec-2025
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The long-term immunogenicity of EnVAX-A71 on SPR
Tidsramme: From Sep-2025 to Dec-2025
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SPR (seroprotection rate, the proportion of the subjects with NTAb against EV71 titer ≥1:32)
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From Sep-2025 to Dec-2025
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The long-term immunogenicity of EnVAX-A71 on the geometric mean titer (GMT) and geometric mean titer ratio (GMTR) of EV71 neutralizing antibody (NTAb)
Tidsramme: From Sep-2025 to Dec-2025
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GMTR (geometric mean titer ratio) is defined as the GMT at the recall visit divided by the GMT at pre-vaccination (Day 0 of main study).
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From Sep-2025 to Dec-2025
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Samarbeidspartnere og etterforskere
Sponsor
Etterforskere
- Studieleder: Wendy Wu, Enimmune Corporation
Studierekorddatoer
Studer hoveddatoer
Studiestart (Faktiske)
Primær fullføring (Faktiske)
Studiet fullført (Faktiske)
Datoer for studieregistrering
Først innsendt
Først innsendt som oppfylte QC-kriteriene
Først lagt ut (Faktiske)
Oppdateringer av studieposter
Sist oppdatering lagt ut (Faktiske)
Siste oppdatering sendt inn som oppfylte QC-kriteriene
Sist bekreftet
Mer informasjon
Begreper knyttet til denne studien
Ytterligere relevante MeSH-vilkår
Andre studie-ID-numre
- EV-BR1701 Part A1 Extension
Plan for individuelle deltakerdata (IPD)
Planlegger du å dele individuelle deltakerdata (IPD)?
Legemiddel- og utstyrsinformasjon, studiedokumenter
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