I think once you grt the twinrix vacination for hep a & b you are good I got mine as soon as I was diagnosed.
Depends on the person. Indefinitely for some, others have to do a second series of shots before it takes. You should ask to be tested for A and B antibodies even if you've had the series recently. With some, even if the vaccines produce antibodies, they can be lost over time and you'll need to be re-vaccinated.