Vaccination paradox: Diffuse knowledge but low adherence to children vaccination recommendations among HBV chronically infected patients in Germany

Aims: Preventing HBV transmission to children requires high vaccination coverage. The aim of this study was to investigate vaccination rates and evaluation of adherence to vaccination recommendations among family members of chronically HBV infected patients.

Methods: This prospective pilot study included 200 patients with chronic HBV (20 to 66 years) that were seen in a large urban academic outpatient clinic at the University of Hamburg. All patients with chronic HBV entering the outpatient clinic were enrolled and interviewed by the same medical doctor. The questionnaire contained 50 questions covering social demographic data, knowledge of HBV, therapeutic compliance and prevention.

Results: Overall, of the 200 questionnaires distributed, all 200 could be analysed. 97% of the patients had knowledge about the existence of an HBV vaccine, 78% were aware that HBV vaccine protects against infection and 82% considered a vaccination of all persons in the household as important. Despite the knowledge of the existence and importance of the vaccine, only 61% of children from chronically infected HBV patients were vaccinated. There was no difference in vaccination rates between patients with or without migration background (p=.88). However, children vaccination rate was significantly higher (p=.0017) among patients with high school degree (85%) compared to patients without high school degree (55%). Interestingly, patients which were informed about the free of charge vaccination program for children up to 18 years in Germany (70%) demonstrated a significantly increased vaccination rate (79%, vs. 28%) (p<0,001). In contrast, the knowledge about the safety of the vaccine had no impact on vaccinating rates. Children from chronically infected women showed higher vaccination rates vs. children from infected men (88% vs. 52%; p=0.0001). Of note, we observed the highest children vaccination rate (96%) within the subpopulation of women who had experienced HBV-diagnosis during pregnancy.

Conclusion: The vaccination rates of children from HBV positive patients are far too low and significantly influenced by school education, gender and awareness of charge free vaccination programs. Awareness programs are definitely needed to increase HBV vaccination rates in children.