caring for my brothers hbv

Hello my name is C and I write this e-mail because I find myself in a difficult situation and would be grateful for your help if possible. I have a brother who was born with a mental retardation due to incompatibility of blood, he is now 34 years and despite having had a few problems, none were as complicated as this, he did blood tests and discovered he had hepatitis virus b, I know this is bad and I don´t know how he got it because he never had risk behaviours at any level. The main problem is that it does not have antibodies to fight the virus which results in a multiplication of the virus randomly unrelenting and yet according to the doctors my brother's liver is healthy and they do not know what to do because they've never seen anything like it . I really wanted to know what to do because I know that my brother is at risk of dying at any moment. In Portugal the doctors do not give a solution, time is passing and I am afraid to wake up tomorrow and find my brother dead... please with all my heart and calling for your generosity ... help me!
Thank you C