HC worker. 1992 Hep B vac, 2004 titer & booster. 2012 labs hep B neg. Labs done last wk; now told that Hep B test is positive?? How can this be?

The vaccine worked. Lab tests aren't perfect and sometimes can be wrong. Or maybe the negative result was from the wrong kind of test. Vaccination makes hepatitis B surface antibody (HBsAb) positive. Tests for surface antigen (HBsAg) or core antibody (HBcAb) remain negative. Most important, you can be sure you are immune and protected by the vaccine -- so no worries.