6-year Antibody Check After Third Vaccination Against Japanese Encephalitis

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

Status

Completed

Phases

Phase 4

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT02039440

Enrollment

Registered

2014-01-17

Start date

2014-02-28

Completion date

2014-06-30

Last updated

2015-02-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Post Other Specified Vaccination Encephalitis

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 description

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.

Interventions

OTHERBlood draw

One-time blood draw

Study design

Allocation

Intervention model

SINGLE_GROUP

Masking

NONE

Eligibility

Sex/Gender

ALL

Age

18 Years to No maximum

Healthy volunteers

Yes

Inclusion criteria

* Subjects who received a booster dose of JE-VC in study IC51-311 * Subjects who are willing to give written informed consent to participate in the trial

Exclusion criteria

* Subjects who received a further dose of any Japanese Encephalitis Vaccine since study IC51-311 * Severe immunosuppression (as result of medical conditions or medication) since study IC51-311, such as history of radiation therapy or cytostatic therapy * simultaneous participation in another clinical study

Design outcomes

Primary

Measure	Time frame
Geometric Mean Titer (GMT) for JEV neutralizing antibodies determined by PRNT	1.5 years

Secondary

Measure	Time frame
Seroprotection Rate (SPR) defined as rate of subjects with JEV neutralizing antibody titers ≥1:10 in a PRNT	1.5 years

Other

Measure	Time frame
Projected mean duration of protection after a booster dose of JE-VC	1.5 years

Countries

Austria

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026