Mayorga, O.* ; Bühler, S.* ; Jaeger, V.K.* ; Bally, S.* ; Hatz, C.* ; Frösner, G. ; Protzer, U. ; van Damme, P.* ; Egger, M.* ; Herzog, C.*
Single-dose Hepatitis A immunization: 7.5-year observational pilot study in nicaraguan children to assess protective effectiveness and humoral immune memory response.
J. Infect. Dis. 214, 1498-1506 (2016)
BACKGROUND: Universal 2-dose hepatitis A virus (HAV) vaccination of toddlers effectively controls hepatitis A. High vaccine costs, however, impede implementation in endemic countries. To test single-dose vaccination as a possible alternative, we initiated an observational, longitudinal study in Nicaragua, to assess protective effectiveness and-through challenge vaccination-humoral immune memory response. METHODS: After a 2003 serosurvey, 130 originally seronegative children received one dose of virosomal HAV vaccine in 2005, followed by yearly serological and clinical assessments until 2012. After 7.5 years, a vaccine booster was administered. Concurrent antibody screening of patients presenting with hepatitis symptoms documented persistent HAV circulation in the communities studied. RESULTS: Between serosurvey and vaccination, 25 children contracted hepatitis A subclinically (>8000 mIU/mL anti-HAV). In the remaining 105 children, immunization resulted in anti-HAV levels of 17-572 mIU/mL. Based on the ≥15% annual infection risk, an estimated 60% of children were exposed to HAV encounters during follow-up. No child presented with hepatitis symptoms. Serological breakthrough infection (7106 mIU/mL) was documented in 1 child, representing an estimated protective effectiveness of 98.3% (95% confidence interval, 87.9-99.8). Boosting elicited an average 29.7-fold increase of anti-HAV levels. CONCLUSIONS: In children living in hyperendemic settings, a single dose of virosomal HAV vaccine is sufficient to activate immune memory and may provide long-term protection.
Impact Factor
Scopus SNIP
Web of Science
Times Cited
Scopus
Cited By
Altmetric
Publication type
Article: Journal article
Document type
Scientific Article
Thesis type
Editors
Keywords
booster interval; children; hepatitis A; hepatitis A vaccine; immune memory; long-term follow-up; protective effectiveness; single-dose vaccination
Keywords plus
Language
Publication Year
2016
Prepublished in Year
HGF-reported in Year
2016
ISSN (print) / ISBN
0022-1899
e-ISSN
1537-6613
ISBN
Book Volume Title
Conference Title
Conference Date
Conference Location
Proceedings Title
Quellenangaben
Volume: 214,
Issue: 10,
Pages: 1498-1506
Article Number: ,
Supplement: ,
Series
Publisher
Oxford University Press
Publishing Place
Day of Oral Examination
0000-00-00
Advisor
Referee
Examiner
Topic
University
University place
Faculty
Publication date
0000-00-00
Application date
0000-00-00
Patent owner
Further owners
Application country
Patent priority
Reviewing status
Peer reviewed
POF-Topic(s)
30203 - Molecular Targets and Therapies
Research field(s)
Immune Response and Infection
PSP Element(s)
G-502700-003
Grants
Copyright
Erfassungsdatum
2016-12-15