I have a non reactive result both for hbsag and anti-hbs and i remember having a vaccine 5yrlears ago. do i still need to get a vaccine? thank you

Probably no need: A new research study, published only 2 weeks ago, showed that even if an anti-HBs is negative, people who have been immunized against hepatitis B remain protected for at least 20-30 years. The only question is whether you received the full course if 3 vaccine doses. If not, or if you aren't sure, re-vaccination might be a good idea.

Yes: Some people have low or negative HepB surface antibody titers some years after their vaccinations. Such persons are considered non-immune to HepB, and should get booster shots. The current recommendation in the U.S. is to get 3 shots all over again, just as if a person had never been vaccinated.