Hepatitis B Community
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antigen test at 16 weeks

Had a negative Hep b antigen test at possible but low risk exposure after 16 weeks.  Is this conclusive?
17 Responses
Avatar universal

no it is not.you should have had hbv vaccine instead of testing for antigen, you still can since antigen was still negative

after vaccine you need to check antibody hbsab and not antigen any more

hbv does not start an infection when it enters our body, it needs to infect macrophages first which are used to transport inside the liver, this may take few weeks or even 6 months although rare.during this time there is no infection and the vaccine still works

vaccine stops working when hbv reaches the liver and starts making hbsag
Avatar universal

even if vaccine may fail so late it makes sense to try it since it is harmless anyway, at 16 weeks your are probably not infected at all but as said before rare cases at 5-6 motnhs may happen
Avatar universal
OK now im confused.  I asked the experts in the STD forum last week and this was their response...


He seemed 100% confident I had no std?
Avatar universal
Also, I find this on the CDC web site:

A blood test is the only way to know for sure. Blood is tested for the presence of specific anti-viral antigens or antibodies.2

The hepatitis B surface antigen, HbsAg, will be detected in an infected person's blood on the average of 4 weeks (range 1-9 weeks) after exposure to the virus. About one out of two patients will no longer be infectious by seven weeks after onset of symptoms. Patients who do not remain chronically infected will be HBsAg-negative by 15 weeks after onset of symptoms.1

Avatar universal
So if I understand this correctly.  Since I didnt have the antibody test, I could have had Hep B but my test at 16 weeks only indicates that I no longer have Hep B if I did?  Meaning Im not chronically infected?
Avatar universal
Sorry, but just to be sure here is the name of the test I had

Hepatitis B Surface Antigen (HBaAg) with reflex confirmation
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