Had Hep A, B Vaccination. Blood Test Showed Borderline Positive HBSAG. Worrisome

Posted on Thu, 24 Jan 2013

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Thu, 24 Jan 2013 Answered on

Sat, 9 Feb 2013 Last reviewed on

Question : Hi, I had my first twinrix (hep A, B) vaccination Dec 5, 2012 and the 2nd XXXXXXX 9, 2013. On XXXXXXX 10, 2013 I had a blood test which indicated HBSAG result is borderline positive. Is it possible that because I'm in the vaccination series that this result is skewed and suggesting I have Hep B? Can the vaccination affect the blood test result?

Answered by Dr. Dr. Michelle Gibson (-5 hours later)

Hi, thanks for using healthcare magic

The hepatitis vaccine that you were given contains the hepatitis B surface antigen (HepBsAG) which is one of the proteins associated with that virus.
Normally after the vaccine is given , the body reacts by producing antibodies to the particular protein. The level of antibodies is checked to ensure that the value is above a certain level which would indicate your body has reacted appropriately to the vaccine.

Some persons do not have a full response and may need further immunisation and retesting of the level.

So the reason for the positive anti HBsAG level is the immunisation.

I hope this helps, feel free to ask any other questions

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar