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

February 5, 2014 updated by: Valneva Austria GmbH
The study investigates the long term persistence the Japanese encephalitis vaccine IC51 and the need of a booster dose

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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 Type

Interventional

Enrollment (Actual)

349

Phase

  • Phase 3

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Other: IC51
In study IC51-305, subjects who had received IC51 in study IC51-304 were tested for seroconversion 6 months after the first vaccination. Subjects who had protective titers were again tested for persistence of immunity at 12 months after the first immunization,whereas subjects who had titers below the seroconversion threshold by Month 6 received a booster dose of 1x6 mcg IC51 at Month 11. Their immune response was also assessed at Month 12. Thereafter, subjects who had no protective titer by Month 12 received a booster dose of 1x6 mcg IC51 at Month 23, regardless of prior treatment; and neutralizing antibody titers were reassessed at Month 24. Subjects who had protective titers at month 12 did not receive a booster at Month 23, and their neutralizing antibody titer was also assessed at Month 24.
Biological: IC51
Other Names:
  • Japanese Encephalitis purified inactivated vaccine

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Long Term Immunogenicity of IC51 Vaccine 24 Months After the Primary Vaccination
Time Frame: - 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
- 24 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
SPR 24 Months After the Primary Vaccination (Observed)
Time Frame: 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)
24 months
Persistent and Actual SPR 6, 12 and 24 Months After Primary Vaccination
Time Frame: - 24 months
- 24 months
Persistent and Actual GMT 6, 12 and 24 Months After Primary Vaccination
Time Frame: 24 months
24 months
SCR 1 Month After the Booster Doses
Time Frame: 1 month
1 month
GMT 1month After Booster Doses
Time Frame: 1 month
1 month
Safety Profile of IC51
Time Frame: study duration
study duration

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Valneva Austria GmbH

Investigators

  • Study Director: Susanne Eder, Valneva Austria GmbH

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

October 1, 2005

Primary Completion (Actual)

September 1, 2007

Study Completion (Actual)

April 1, 2009

Study Registration Dates

First Submitted

January 4, 2008

First Submitted That Met QC Criteria

January 4, 2008

First Posted (Estimate)

January 16, 2008

Study Record Updates

Last Update Posted (Estimate)

March 7, 2014

Last Update Submitted That Met QC Criteria

February 5, 2014

Last Verified

February 1, 2014

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IC51-305

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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