Wow - very informative. Thank you.
Your question is non-trivial. It goes to the issue of different HBV genotypes and superinfection with more than one genotype of HBV. I have not come across any scientific literature dealing specifically with this. It must be a fairly common issue in HBV endemic area, such as China. If both are under treatment, I don't think it will be any issue, or if both have the same genotype of HBV.
Curious too, and just my opinion.
Please note I a not a doctor, but it seems like similar situations.
Before I found out that my baby developed antibodies and is protected, I asked my liver specialist what happens if she is already infected and she gets more of my virus in her, my doctor said it makes no difference. The amount of virus you may get in you after an infection is insignificant if you are already infected.
So to answer your question, yes, there's a little increase, but not enough to make any difference.
This too may sound like a dumb question.
dose having sex with someone who's also infected, dose it put a little increase in the amount of virus in your body?
Dumb question. You should be fine if both have it and are being treated. Even if not treated and you both have it, it's fine. It's when one person has it and the other does not which poses the risks. Even if such is the case, you can but use protection.