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

Vaccine. 2015 Oct 13;33(42):5723-5727. doi: 10.1016/j.vaccine.2015.07.008. Epub 2015 Jul 16.


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.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Hepatitis A / prevention & control
  • Hepatitis A Antibodies / blood*
  • Hepatitis A Vaccines / administration & dosage*
  • Humans
  • Immunization, Secondary
  • Linear Models
  • Male
  • Middle Aged
  • Vaccination / methods*
  • Vaccines, Inactivated / administration & dosage


  • Hepatitis A Antibodies
  • Hepatitis A Vaccines
  • Vaccines, Inactivated

Associated data

  • ClinicalTrials.gov/NCT00289757
  • ClinicalTrials.gov/NCT00291876