My 3 years old had all 3 hep b vaccines at her l 4days, 2 moths and 6 months. She recently tested for her hep b showing she is Hbsab positive and Hbsag preliminary reactive. When they do the hbsag neutralization test, the result came back indeterminate. So does she has hep b? I am so confused and nervous. I read some articles that she may have the mutant infection.
Hep B Surface Antigen Index. 6.9 sco
Hep B Surface Antigen. Preliminary reactive
HBsAg Confirmatory. Indeterminate
(The presence of Hepatitis B Antigen could not be confirmed by neutralization.)
Hepatitis B Surface Antibody. 52.7
(Normal range: above >=8.00 miu/ mI)
She is also on a formula which contains 30mcg biotin (total 60mcg daily), i don’t know if that may interfere the lab result.
*I am vaccinated when i was a teenager and tested negative Hbsag when I was pregnant. Her father just found out that he has chronic hep b that’s why we did tests for our daughter.
I’m not a physician and cannot give formal diagnoses, but I’ll tell you what this pattern typically means.
Being HBsAg positive means that there is viral DNA in her body making the antigen. That is usually from virus that is replicating in the liver for someone as young as she is. The inability to clearly identify HBs antibody or to confirm the presence of HBsAg in the followup tests means that either the first test was in error (not common with clinical tests, but possible when levels are very low), or that she has both HBsAg and HBsAntibody in her blood. In that case the antibody is reacting with the antigen and blocking the ability of the assays to clearly detect either the antibody or antigen. That is a bit unusual but can happen.
The vaccine is great, but it has a ~5-7% failure rate (I’m a non-responder despite being vaccinated twice), so it could be that your daughter was just a weak responder and that let the virus gain a foot hold in her. Also, giving the first dose of vaccine at 4 days of age is a bit late to prevent vertical transmission.
I recommend speaking with your physician. Seeking additional tests for HBcAg and HBV DNA will clarify things.
I wish you and your family the very best. This is a really stressful time for your family, and I am sorry that you need to go through this.
I am not an expert. I noticed the HBsAg test is using sco(signal-to-cutoff ratio). I would like to suggest using enzyme-linked immunosorbent assay (ELISA) for a re-test. Since you were HBsAg negative when pregnant, it would be doubtful that if the HBV infection was vertically transmitted. The presence of HBsAb is reassuring. A full panel of HBV tests including HBcAb and hbvdna would be more informative.