the problem with hbv is that it blocks immune system and neutralize your hbsab antibodies by overproduction of hbsag, we all have immunity antibodies but they are neutralized by hbsag and probably other way hbv virus uses to suppress our imune response
so there are only 2 ways: decrease hbsag or find a way to unblock immune system and rise hbsab
ntz works by unblocking immune system at cellular level (PKR .....) and maybe by blocking hbsag releaze from cells like for flu viruses, this way hbsag decreaes and your hbsab antibodies rise
if hbsag gets to zero (lucky ones and who knows how many) your hbsab antibodies are present so vaccine is totally useless