Long Term Persistence and Effect of a Booster Dose of the Japanese Encephalitis Vaccine IC51

Phase 3

Completed

• Conditions: Japanese Encephalitis

• Registration Number: NCT00595270
• Lead Sponsor: Valneva Austria GmbH

Brief Summary

The study investigates the long term persistence the Japanese encephalitis vaccine IC51 and the need of a booster dose

Detailed Description

This is an open label, non-randomized multi-center phase 3 follow-up study. All volunteers having completed trial IC51-304 (NCT00595790) will be enrolled into this trial at 2 sites

Study Timeline

• Study Start: 2005-10
• Primary Completion: 2007-09
• Study First Submitted: 2008-01-04
• Study First Submitted QC: 2008-01-04
• Study First Posted: 2008-01-16
• Study Completion: 2009-04
• Results First Submitted: 2013-12-05
• Status Verified: 2014-02
• Results First Submitted QC: 2014-02-05
• Last Update Submitted: 2014-02-05
• Results First Posted: 2014-03-07
• Last Update Posted: 2014-03-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 349

Inclusion Criteria

• At least 18 years of age
• Written informed consent obtained prior to study entry
• Subjects correctly included in and having completed study IC51-304 according to the protocol.

Exclusion Criteria

• Use of any other investigational or non-registered drug or vaccine in addition to the study vaccine during the study period
• Immunodeficiency including post-organ-transplantation or immunosuppressive therapy
• Pregnancy, lactation or unreliable contraception in female subjects

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Long Term Immunogenicity of IC51 Vaccine 24 Months After the Primary Vaccination	- 24 months	Seroprotection rate (SPR) (anti-JEV neutralizing antibody titer ≥ 1:10) 24 months (M24) after the primary vaccination - imputed; Persistence of immunogenicity (SPR) at M24 defined as: * pos. (positive) (persistent): Subjects; * with a non-missing, pos. seroconversion at D56 (Study IC51-304) and; * without booster at M11 or M23 and; * with non-missing, seroprotection (SP) pos. PRNT50 at M6 or M12 and; * with non-missing, SP pos. PRNT50 at M24; * neg. (negative) (non-persistent): Subjects with; * missing or neg. seroconversion at D56 (Study IC51-304) or; * booster at M11 or at M23, or; * non-missing, SP neg. PRNT50 at M6 or M12 or; * missing PRNT50 at both M6 and M12 or; * missing or SP neg. PRNT50 (serum dilution giving 50% reduction in plaques in a Plaque Reduction Neutralization Test) at M24

Secondary Outcome Measures

Name	Time	Method
Persistent and Actual GMT 6, 12 and 24 Months After Primary Vaccination	24 months
SCR 1 Month After the Booster Doses	1 month
GMT 1month After Booster Doses	1 month
Safety Profile of IC51	study duration
SPR 24 Months After the Primary Vaccination (Observed)	24 months	Persistence of immunogenicity (SPR) at M24 (observed) defined as : * positive (persistent): Subjects; * with a non-missing, positive seroconversion at D56 (Study IC51-304), and; * who did not receive a booster dose at Visit 2 (M11) or Visit 4 (M23), and; * with a non-missing, SP positive PRNT50 result at Visit 1 (M6) or Visit 3 (M12), and; * with a non-missing, SP positive PRNT50 result at Visit 5 (M24); * negative (non-persistent): Subjects; * with missing or negative seroconversion at D56 (Study IC51-304), or; * who did receive a booster dose at Visit 2 (M11) or at Visit 4 (M23), or; * with a non-missing, SP negative PRNT50 result at Visit 1 (M6) or Visit 3 (M12), or; * with a missing PRNT50 result at both Visit 1 (M6) and Visit 3 (M12), or; * with a non-missing, SP negative PRNT50 result at Visit 5 (M24)
Persistent and Actual SPR 6, 12 and 24 Months After Primary Vaccination	- 24 months