Det kan forventes, at immunisering med Fendrix også beskytter mod hepatitis D (forårsaget af delta virus), da hepatitis D ikke forekommer, når der ikke er infektion med hepatitis B- virus.
It can be expected that hepatitis D will also be prevented by immunisation with Fendrix as hepatitis D (caused by the delta agent) does not occur in the absence of hepatitis B virus infection.