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

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00595270
First Posted: January 16, 2008
Last Update Posted: March 7, 2014
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
Valneva Austria GmbH
  Purpose
The study investigates the long term persistence the Japanese encephalitis vaccine IC51 and the need of a booster dose

Condition Intervention Phase
Japanese Encephalitis Biological: IC51 Phase 3

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Prevention
Official Title: Long Term Persistence and Effect of a Booster Dose of the Japanese Encephalitis Vaccine IC51

Resource links provided by NLM:


Further study details as provided by Valneva Austria GmbH:

Primary Outcome Measures:
  • 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


Secondary Outcome Measures:
  • 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)

  • Persistent and Actual SPR 6, 12 and 24 Months After Primary Vaccination [ Time Frame: - 24 months ]
  • Persistent and Actual GMT 6, 12 and 24 Months After Primary Vaccination [ Time Frame: 24 months ]
  • SCR 1 Month After the Booster Doses [ Time Frame: 1 month ]
  • GMT 1month After Booster Doses [ Time Frame: 1 month ]
  • Safety Profile of IC51 [ Time Frame: study duration ]

Enrollment: 349
Study Start Date: October 2005
Study Completion Date: April 2009
Primary Completion Date: September 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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 Name: Japanese Encephalitis purified inactivated vaccine

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
  Eligibility

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

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
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00595270


Sponsors and Collaborators
Valneva Austria GmbH
Investigators
Study Director: Susanne Eder Valneva Austria GmbH
  More Information

Responsible Party: Valneva Austria GmbH
ClinicalTrials.gov Identifier: NCT00595270     History of Changes
Other Study ID Numbers: IC51-305
First Submitted: January 4, 2008
First Posted: January 16, 2008
Results First Submitted: December 5, 2013
Results First Posted: March 7, 2014
Last Update Posted: March 7, 2014
Last Verified: February 2014

Additional relevant MeSH terms:
Encephalitis
Encephalitis, Japanese
Brain Diseases
Central Nervous System Diseases
Nervous System Diseases
Encephalitis, Arbovirus
Arbovirus Infections
Virus Diseases
Encephalitis, Viral
Central Nervous System Viral Diseases
RNA Virus Infections
Flavivirus Infections
Flaviviridae Infections
Infectious Encephalitis
Central Nervous System Infections
Vaccines
Immunologic Factors
Physiological Effects of Drugs