Longterm Immunogenicity of the Japanese Encephalitis Vaccine IC51

Longterm Immunogenicity of the Japanese Encephalitis Vaccine IC51. An Uncontrolled Phase 3 Follow-up Study

The study investigates the long term safety and immunogenicity of the Japanese Encephalitis vaccine IC51 up to month 60.

Study Overview

• Status: Completed
• Conditions: Japanese Encephalitis
• Intervention / Treatment: Biological: Japanese Encephalitis purified inactivated vaccine

• Study Type: Observational
• Enrollment (Actual): 3258

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Approximately 3,300 subjects having completed IC51, JE-VAX or placebo treatment in studies IC51-301 or IC51-302 will take part in the safety follow up, up to month 6 after 1st vaccination in the study IC51-301 (NCT00604708) or IC51-302 (NCT00605085).

Only ~160 subjects, who have been treated with IC51 will take part in the immunogenicity and long-term analysis up to month 60.

Description

Inclusion Criteria:

• Healthy subjects at least 18 years of age
• Written informed consent obtained prior to study entry
• Subjects correctly included and having completed clinical studies IC51-301 (NCT00604708) and IC51-302 (NCT00605085) with at least one vaccination

Exclusion Criteria:

• Inability or unwillingness to provide informed consent and to abide the requirements of the study

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Subjects With Seroconversion Rate (SCR) ≥ 1:10 Anti-JEV Neutralizing Antibody Titer (PRNT)	first vaccination refers to 1st vaccine administration in studies IC51-301 or IC51-302	24 months after the first vaccination

Secondary Outcome Measures

Outcome Measure	Time Frame
Percentage of Subjects With Seroconversion Rate (SCR) ≥ 1:10 Anti-JEV Neutralizing Antibody Titer (PRNT)	6, 12, 36, 48 and 60 months after 1st vaccination
Geometric Mean Titers	6, 12, 36, 48 and 60 months
Adverse Events	6, 12, 24, 36, 48 and 60 months after 1st vaccination

Collaborators and Investigators

• Sponsor: Valneva Austria GmbH
• Investigators: Study Director: Evelyn Hatzenbichler, Ph.D., Valneva Austria GmbH

Publications and helpful links

General Publications

• Taucher C, Kollaritsch H, Dubischar KL. Persistence of the immune response after vaccination with the Japanese encephalitis vaccine, IXIARO(R) in healthy adults: A five year follow-up study. Vaccine. 2019 May 1;37(19):2529-2531. doi: 10.1016/j.vaccine.2019.03.030. Epub 2019 Apr 5.

Study record dates

Study Major Dates

• Study Start: October 1, 2005
• Primary Completion (ACTUAL): March 1, 2011

Study Registration Dates

• First Submitted: January 4, 2008
• First Submitted That Met QC Criteria: January 15, 2008
• First Posted (ESTIMATE): January 16, 2008

Study Record Updates

• Last Update Posted (ESTIMATE): July 30, 2014
• Last Update Submitted That Met QC Criteria: June 27, 2014
• Last Verified: June 1, 2014

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; RNA Virus Infections; Virus Diseases; Infections; Encephalitis, Arbovirus; Encephalitis, Viral; Central Nervous System Viral Diseases; Central Nervous System Infections; Infectious Encephalitis; Arbovirus Infections; Vector Borne Diseases; Flavivirus Infections; Flaviviridae Infections; Encephalitis, Japanese; Encephalitis
• Other Study ID Numbers: IC51-303