Had 2 of 3 Hep B vaccine shots. HEPATITIS B SURFACE ANTIBODY QL is NON-REACTIVE. 3rd shot in June. Am I protected at all until final shot?

Immune System. The Immune System is quite mysterious - it has layers and layers to it actually. One 'crude' way of measuring part of this immunity is through antibody testing. That only measures one branch of the whole thing, however. With Hep B vaccine especially, there is often good T-cell immunity generated, which is NOT routinely measured. You're not quite done with the series, so I would measure afterwards.