Background: Not many data are available on long-term immunity against hepatitis B (HB) for children vaccinated under real-life conditions.
Methods: Two hundred and thirty-two children and adolescents vaccinated 6–14 years earlier in pediatric practices were examined for conditions of vaccination and markers of protection as anti-HBs, anamnestic response to a booster dose and cell-mediated immunity.
Results: Fifty-six percent of the participants were vaccinated according to the German vaccination recommendations (group 1). In 44.0% (group 2), these recommendations were not followed. Anti-HBs concentrations of ≥10 IU/L were found in 53.1% of group 1 and 45.1% of group 2 participants. A booster dose resulted in 91 of 99 participants in having an anamnestic response, in 3 (5.9%) of group 1 and 5 (10.4%) of group 2 anti-HBs remained below 10 IU/L. In group 1, postbooster anti-HBs concentration was inversely correlated with time since the last vaccination. Cellular immune responses were seen in only 5% of revaccinated individuals before the booster, increasing to 30% thereafter.
Conclusions: Under real-life conditions about half of vaccinees have lost protecting antibodies 6–14 years after vaccination in infancy, but in approximately 90% of them, immune memory was demonstrated. However, as memory may wane, revaccination at a time when boostability is still present might be considered.
From the *Institute of Medical Microbiology and Hygiene, and †Institute of Clinical Microbiology and Hygiene, University of Regensburg, Regensburg, Germany.
Accepted for publication September 9, 2015.
I.B.H. and B.H. contributed equally to this work.
This work was supported by Robert Koch-Institute (grant number: 1362/1–926). The funding source was not involved in the study design, in the collection, analysis and interpretation of data, in the writing of the report and in the decision to submit the article for publication. W.J. has received honoraria for lectures from GlaxoSmithKline and SanofiPasteur-MSD and served as principal investigator in a clinical trial on hepatitis B vaccination sponsored by GlaxoSmithKline. The authors have no other funding or conflicts of interest to disclose.
Address for correspondence: Irena Brunskole Hummel, PhD, Institute of Medical Microbiology and Hygiene, University of Regensburg, Franz-Josef-Strauß-Allee 11, 93053 Regensburg, Germany. E-mail: firstname.lastname@example.org.