How long does hepatitis b vaccine stay effective in your system?

Hepatitis b vaccine: If you have completed the series whic is three shots.Second given 1 month after the first one and third after 4 months of the second shot.So far it seems the immunity holds for life but it has still to be seen as Hepatitis B Vaccine was started only in eighties.Hepatitis vaccine does not stay in your system it produces antibodies to make you immune against hepatitis b virus and you do not get dise

20+ years: Hepatitis b vaccine provides protection at least 20 years.

Hard to be sure: The present era of Hepatitis B vaccines was entered in the US in 1983 when the first recombinant (lab made) product was approved for use by the FDA. Other formulations have emerged & another approved recently. It was the mid 1990's before it was in common use. The series is expected to have the ability to create indefinite protection, but confirmation beyond 25 yrs will take time.