If you tested HBsAb positive sometime back, you are immune.
While i had taken my last vaccine at last 2year, i had also tested HBsAb.
That was positive.
I want to know can that result be changed within 2or 3years?
do you said that after i have taken HB vaccine for 4times there is still a chance to infect for me?
test yourself for HBsAb. If you test positive, you are immune for life.