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 (27 minutes 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