Hos hæmodialysepatienter og personer med svækket immunsystem opnås ikke altid adækvat anti- HAV og anti- HBs antistoftiter efter det primære immuniseringsprogram, hvorfor sådanne patienter kan have behov for yderligere doser af vaccinen.
In haemodialysis patients and persons with an impaired immune system, adequate anti-HAV and anti-HBs antibody titers may not be obtained after the primary immunisation course and such patients may therefore require administration of additional doses of vaccine.