Intradermal hepatitis B vaccination in non-responders after topical application of imiquimod (Aldara®)

Trial registration: NTR1043 (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1043).BackgroundFive to ten percent of immunocompetent persons fail to develop a protective immune response to hepatitis B vaccination, and are defined non-responders (NR). We investigated the immune response to intradermal hepatitis B vaccination after pre-treatment of the skin with the TLR7 agonist imiquimod.MethodsTwenty-one non-responders (anti-HBs <10 IU/l after at least 6 intramuscular hepatitis B vaccinations) were randomly assigned to the control group (N = 11) or the experimental group (N = 10). Participants in both groups received 3 intradermal (ID) vaccinations with 5 μg HBsAg (0.125 mL) at 0, 1 and 6 months. In the experimental group, the dermal site of injection was pre-treated with 250 mg imiquimod ointment. Anti-HBs antibodies were determined at 0, 1, 2, 6 and 7 months.ResultsIn both study groups, 70% of the participants developed a protective immune response (anti-HBs ≥10 IU/l), after the 3rd intradermal vaccination.ConclusionThe application of imiquimod on the skin prior to intradermal vaccination did not enhance the humoral response to hepatitis B vaccine. However, irrespective of imiquimod application, 70% of the NR who had not responded to 6 previous intramuscular vaccinations, developed a protective immune response with high affinity antibodies after 3 ID hepatitis B vaccinations with 5 μg HBsAg.