Usually blood. World-wide mostly obtained at birth (vertical transmission) from infected mother to newborn; commonly chronic carrier. In us native born (not asian, african, middle eastern) mostly from IV drug use, occasionally from sexual contacts, needle stick injuries (md, rn, emt, dds). Blood supply tested for years-generally quite safe.
I am wondering about hepatitis b. How do you get it? Is it only by sexual contact or can there be other ways?
See below. One can contract the hepatitis b virus via sexual activity and contact with blood, such as via needles, accidents, or blood transfusions (although this is uncommon nowadays).
Two ways. Hepatitis b is spread via sexual contact or via exposure to contaminated blood (such as IV drug use with shared needles, tattoos done in a non-sterile fashion).
If gf had hep b as a baby and is dormant now (not chronic) can I get it from her through sexual contact? I have received all 3 vaccine shots.
Probably safe. First of all, the vaccination should protect you, but nothing in life is 100%. Secondly, as long as her hep b antigen and viral dna tests are negative, then she's not contagious.
If your vaccine... "took" (detectable titers of anti-hepatitis b surface antibody are present in therapeutic amounts), then you are likely protected. If there is any doubt, ask your girfriend to get tested to check her viral load while you have your antibody levels assessed. If the latter are low, you may need a booster. Above all, be careful to avoid exposure in an unprotected setting.