title: Long-term antibody persistence after vaccination with a 2-dose Havrix (inactivated hepatitis A vaccine): 20 years of observed data, and long-term model-based predictions.
abstract: Antibody persistence in two cohorts of adults, who received inactivated hepatitis A (HAV) vaccine (1440El.U; Havrix; GSK Vaccines) according to a 0-6 or 0-12 month schedule in 1992-1993, has been measured annually. After 20 years, >97% of the subjects in both studies were seropositive for anti-HAV antibodies. Geometric mean concentrations in the according-to-protocol cohorts were 312 mIU/ml in 34/36 subjects vaccinated initially at 0-6 months (NCT00289757) and 317 mIU/ml in 85/86 subjects vaccinated at 0-12 months (NCT00291876). Over the whole follow-up period, seven subjects (2+5, respectively) lost circulating anti-HAV antibodies but mounted a strong response after HAV booster administration (1440El.U). Mathematical modelling, which was applied to assess true persistence at Year 20 (accounting for drop-outs and missing data), and to predict longer-term persistence confirmed previous estimates that seropositive anti-HAV levels would persist in ≥95% vaccinees at Year 30 and ≥90% at Year 40. ClinicalTrials.Gov number: NCT00289757/NCT00291876.
authors.affiliation: Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium.
authors.forename: Heidi
authors.initials: H
authors.lastname: Theeten
authors.affiliation: Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium; Department of Public Health, Ghent University, Ghent, Belgium.
authors.forename: Koen
authors.initials: K
authors.lastname: Van Herck
authors.affiliation: GlaxoSmithKline Wavre, Belgium and Mumbai, India.
authors.forename: Olivier
authors.initials: O
authors.lastname: Van Der Meeren
authors.affiliation: GlaxoSmithKline Wavre, Belgium and Mumbai, India.
authors.forename: Priya
authors.initials: P
authors.lastname: Crasta
authors.affiliation: Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium. Electronic address: pierre.vandamme@uantwerpen.be.
authors.forename: Pierre
authors.initials: P
authors.lastname: Van Damme
authors.affiliation: Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium; Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Diepenbeek, Belgium.
authors.forename: Niel
authors.initials: N
authors.lastname: Hens
mesh_terms: D000328:Adult; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006506:Hepatitis A / Q000517:prevention & control; D035922:Hepatitis A Antibodies / Q000097:blood*; D022362:Hepatitis A Vaccines / Q000008:administration & dosage*; D006801:Humans; D007117:Immunization, Secondary; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D014611:Vaccination / Q000379:methods*; D015164:Vaccines, Inactivated / Q000008:administration & dosage
chemical_list: D035922:Hepatitis A Antibodies; D022362:Hepatitis A Vaccines; D015164:Vaccines, Inactivated
keywords: Immunogenicity; Inactivated hepatitis A vaccine; Long-term follow-up; Mathematical modelling