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
Heidi Theeten, Koen Van Herck, Olivier Van Der Meeren, Priya Crasta, Pierre Van Damme, Niel Hens, Heidi Theeten, Koen Van Herck, Olivier Van Der Meeren, Priya Crasta, Pierre Van Damme, Niel Hens
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.
Keywords: Immunogenicity; Inactivated hepatitis A vaccine; Long-term follow-up; Mathematical modelling.
Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Source: PubMed