Children of Chronic Heb B mum

Hi, this is my first post and I’d like to get some advice.

I have two children (6 and 3) and they have both received their first dose of vaccine and Immunoglobulin-VF at birth and completed the other 2 doses according to the Australian immunization schedule.

My eldest child had Hep B Serology blood tests done at 4 years old and here are the results :
Hep B Surface Antigen (CMIA) Not detected
Hep B Surface Ab (CMIA) 282.2 mIU/mL
Hep B Core Total Ab (CMIA) Not detected
Comment: No evidence of current or past hepatitis B infection. Immune to hepatitis B. Hepatitis B surface antibody levels of equal to or greater than 10 mIU/mL in immunocompetent patients following immunisation indicates that the person will be protected against disease. Subsequent loss of detectable antibody on testing does not mean loss of protection.

From my understanding, my eldest child is protected - Am i correct?

However, with my youngest who had blood tests done recently, the results were very different:

Hep B Surface Antigen (CMIA) Not detected
Hep B Surface Ab (CMIA) <10.0 mIU/mL
Comment: No evidence of current hepatitis B infection. No evidence of immunity to hepatitis B virus. A hepatitis B surface antibody level of equal to or greater than 10 mIU/mL is considered protective. However, if the person is known to have completed hepatitis B vaccination in the past and serologically responded, then later non-reactive antibody results do not indicate loss of protection.

From my understanding, my youngest does not have the virus but also does not have any immunity. How is this possible? My GP said that it is not uncommon for children at this age to not have any immunity detected but that does not mean they are not protected so long they have received all the required vaccines. Is this true?

We took the GP advice and gave my youngest another booster shot and will repeat the blood test in a month. I’m just getting so anxious and can’t imagine what if my youngest is a vaccine non-responder. What’s the odd? I will be living in constant fear and guilt what if my youngest has contracted the virus from me? I know logically the risk is low but I can’t help thinking the worse (I am currently on treatment for my high viral load and taking Entecavir).

Thank you for reading my long post!

Dear @Hazel ,

Welcome to the forum, we are glad you found us.

For your eldest child:
No evidence of infection and protection is in place.

For your youngest child:
We are missing the Core total Ab test, can you provide this?
There is no active infection present and your child may have HBsAb just below the threshold. This will still provide protection.

In some individuals, vaccine response can be suboptimal. The booster approach here is correct.

There is no reason to be worried here…your youngest child is HBsAg negative. We do need to see the HBcAg total Ab test though.

Keep us informed!


Thank you @availlant for your quick response. Unfortunately, we werent provided the result for the Core Total Ab. Initially only the HBsAg came back and nothing else. My GP was confident that everything will turn out okay but for our peace of mind, I insisted that they should check for immunity. Tbh I was unsure of the remainder blood sample being more than a week old but my GP didn’t think it matters and that the result for HBsAb would not be affected.

Could you please tell me what does Core Total Ab check for? I still get confused at times.

I will request for it when we repeat the blood test in a month time.

Thanks again.

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Hi @Hazel ,

Inside the HBV virus, there is a protein shell called the capsid which houses the genetic material of the virus (aka HBV DNA). The capsid is formed from many individual HBV core proteins. Infection by HBV drives the development of antibodies to these core proteins. The Core Total Ab test checks for two types of antibodies to the core protein, one type present only during acute infection and the other which is always present, regardless of how long the HBV infection has been present.

So in your older child, the negative total core Ab test is definitive for no established infection.

Best regards,

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