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Completed

NCT Number: NCT00595270

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

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

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Key information

Conditions

Japanese Encephalitis Arbovirus Infections Brain Diseases Central Nervous System Diseases Central Nervous System Infections Central Nervous System Viral Diseases Encephalitis Encephalitis, Arbovirus Encephalitis, Japanese Encephalitis, Viral Flaviviridae Infections Flavivirus Infections Infections Infectious Encephalitis Mosquito-Borne Diseases Nervous System Diseases Neuroinflammatory Diseases RNA Virus Infections Vector Borne Diseases Virus Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

About this study

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

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

IC51

Biological

Other names: Japanese Encephalitis purified inactivated vaccine

Primary outcomes

  1. 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 outcomes

  1. 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)

  2. Persistent and Actual SPR 6, 12 and 24 Months After Primary Vaccination

    Time frame: - 24 months

  3. Persistent and Actual GMT 6, 12 and 24 Months After Primary Vaccination

    Time frame: 24 months

  4. SCR 1 Month After the Booster Doses

    Time frame: 1 month

  5. GMT 1month After Booster Doses

    Time frame: 1 month

  6. Safety Profile of IC51

    Time frame: study duration

Sponsors and collaborators

Lead sponsor

Valneva Austria GmbH

Industry

Registry information

Important dates

Study start
2005
Primary completion
2007
Study completion
2009
First posted
Jan 16, 2008
Registry last updated
Mar 7, 2014

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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