Neutralizing antibody persistence in pediatric travelers from non-JE-endemic countries following vaccination with IXIARO® Japanese encephalitis vaccine: An uncontrolled, open-label phase 3 follow-up study. Issue 34 (March 2020)

• Record Type: Journal Article
• Authors: Taucher, Christian; Barnett, Elizabeth D.; Cramer, Jakob P.; Eder-Lingelbach, Susanne; Jelinek, Tomas; Kadlecek, Vera; Kiermayr, Sigrid; Mills, Deborah J.; Pandis, Duellyn; Reiner, Daniela; Dubischar, Katrin L.
• Is Part Of: Travel medicine and infectious disease. Issue 34(2020)
• Publication Date: 2020-03
• Subjects: Japanese encephalitis vaccine -- Immunogenicity -- Antibody persistence -- Children -- Seroprotection -- IXIARO®; Travel -- Health aspects -- Periodicals; Communicable diseases -- Periodicals; Tropical medicine -- Periodicals; 610.5
• DOI: 10.1016/j.tmaid.2020.101616
• Languages: English
• ISSNs: 1477-8939

Abstract

Abstract: Background: In an initial study among children from non-Japanese encephalitis (JE)-endemic countries, seroprotection rates remained high 6 months after completion of the primary series with IXIARO® . Methods: In this open-label follow-up study, a subset of 23 children who received a 2-dose primary series of IXIARO® in the parent study, were evaluated for safety and neutralizing antibody persistence for 36 months. Results: Seroprotection rates (SPRs) remained high but declined from 100% one month after primary immunization to 91.3% at month 7 and 89.5% at month 36. Geometric mean titers (GMTs) declined considerably from 384.1 by day 56–60.8 at month 36. No long-term safety concerns were identified. Conclusions: The substantial decline in GMT observed in this study, together with previously published data on children vaccinated with IXIARO® support the recommendation for a booster dose in children who remain at risk of JE from 1 year after the primary series of IXIARO®, consistent with the recommendation for adults. Clinical trial registry number: NCT01246479 .