Clinical Trial: 6-year Antibody Check After Third Vaccination Against Japanese Encephalitis

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: Neutralizing Antibody Titers 6 Years After the Third Dose of Inactivated Japanese Encephalitis Vaccine and Projected Duration of Protection

Brief Summary: The purpose of this study is to determine whether there are persisting antibodies against Japanese Encephalitis 6 years after the last vaccination with IXIARO(R) and to adapt or confirm mathematical models accordingly.

Detailed Summary:

Japanese Encephalitis (JE) is a potentially devastating mosquito-borne viral disease. The JE virus (JEV), a Flavivirus, is endemic to many regions in Asia, and while JE is primarily a pediatric disease in the endemic regions, travelers from non-endemic regions to Asia are usually naïve to the virus and may be at risk for contracting JE at any age.

The present study aims to investigate antibody titers at approximately 6 years after the third dose of JE vaccine (JE-VC), in a cohort of participants from an earlier booster dose trial, to strengthen the statistical model of the duration of protection after the booster.

Sponsor: Medical University of Vienna

Current Primary Outcome: Geometric Mean Titer (GMT) for JEV neutralizing antibodies determined by PRNT [ Time Frame: 1.5 years ]

Original Primary Outcome: Same as current

Current Secondary Outcome: Seroprotection Rate (SPR) defined as rate of subjects with JEV neutralizing antibody titers ≥1:10 in a PRNT [ Time Frame: 1.5 years ]

Original Secondary Outcome: Same as current

Information By: Medical University of Vienna

Dates:
Date Received: January 16, 2014
Date Started: February 2014
Date Completion:
Last Updated: February 20, 2015
Last Verified: February 2015