HBV Vaccination

I was vaccinated for Hep B 4 years ago with a series of three injections.  Shortly after vaccinated, my surface ABs were measured quantitatively at 131 (Greater than 10 is considered to be immune).  Today my qualitative surface AB tests negative, but my quantitative surface AB is positive with a count of 2.  My questions are (1) is there any relevance to the disparity of the negative qualitative test but a positive quantitative test?  (2) Am I still immune now that the titers are < 10? Totally healthy otherwise.  No immune system problems at all.

[Kevin Pho, MD]

The decrease of the test would suggest that you are no longer immune to hepatitis B.  The overall immunization success rate is about 95 percent, which decreases as one ages (86 percent in the fourth decade, 47 percent in the sixth decade).  

You may want to discuss the option of getting re-immunized.  

Followup with your personal physician is essential.

This answer is not intended as and does not substitute for medical advice - the information presented is for patient education only. Please see your personal physician for further evaluation of your individual case.

Kevin, M.D.
kevinmd_b

[charlie_muse]

I work in a diagnostic laboratory and can answer your question.  

A result showing immunity to Hepatitis B gives a result of a quantitative antibody titre of greater than 100 IU/ml. Less than 10 gives (for example your result 2) gives a qualitative negative result even though there are a few antibodies detected. Between 10-100 is partial immunity although a booster dose is advisable as you are not fully protected to the Hepatitis B virus.