Understanding how vaccination and low viral load impacts transmission

Hey everyone,

I’m new here and think this community is amazing. I have a potential partner who has had chronic hbv from birth. She is very brave and communicated this to me in confidence. I’m trying to understand more about her condition. My questions are:

  1. Everywhere I see, I read either that the vaccine prevents infection or makes it unlikely (negligible chance). I am trying to understand what negligible means, is it a 1% chance? Also is there still a chance of getting infected even if I end up getting a titre and see antibodies? I thought having anti-bodies would mean there is 0% chance of getting the virus. I haven’t been able to find a conclusive answer to this.

  2. Is kissing still ok? Again, I see conflicting claims on the internet.

  3. If someone has a low viral load, I know the chances of transmission are less, but can viral loads re-activate and increase at some points, increasing the chances of transmission?

  4. If I don’t get hbv after being sexually involved with someone once, can I ever get it from them? i.e does frequency of sexual contact change the likelihood of transmission?

Thank you for all your help. This is the best resource related to hepB I have found and has helped me be supportive of this amazing person I have gotten to know over the past few months.

1 Like

Dear moonmoon,
First, I welcome you most sincerely to our community although you are negative and would wish to be guided so that you may know how to conduct yourself as you relate with your new found lover.
I am very proud of your girlfriend for being bold by opening herself to you to avoid future heartbreaks. Pass my kudos to her. Back to your concerns, since they are specific, I would urge to be abit patient that you can get reliable and complehensive answers from our expertise.
Be assured you have found your right direction.
Regards
Kinoti

Dear @moonmoon,

Welcome to the forum. That’s great news that your potential partner is so open and that you recognise the bravery it took. Thanks for your questions and your willingness to learn.

To answer your questions:

  • Everywhere I see, I read either that the vaccine prevents infection or makes it unlikely (negligible chance). I am trying to understand what negligible means, is it a 1% chance? Also is there still a chance of getting infected even if I end up getting a titre and see antibodies? I thought having anti-bodies would mean there is 0% chance of getting the virus. I haven’t been able to find a conclusive answer to this.

This is more of a question of vocabulary. In science (particularly medical science and biology), we almost never say “never” or “completely zero” unless it is part of a definition. By using the word negligible we are saying that it happens at such a low rate that we don’t consider it, but leave the possibility open that it could occur (just at a rate so low that we can’t detect it). To my knowledge, there is no good data on the specific percentage because the experiment to do this would be extremely difficult to do. But we know the vaccine is very very effective and there is a very very low chance of getting a chronic infection if you .

  • Is kissing still ok? Again, I see conflicting claims on the internet.

Kissing is fine - Your Sexual Health and Hepatitis B! - Hepatitis B Foundation for more information

  • If someone has a low viral load, I know the chances of transmission are less, but can viral loads re-activate and increase at some points, increasing the chances of transmission?

Yes, this is possible. It’s always good to maintain monitoring to make sure viral loads are low.

  • If I don’t get hbv after being sexually involved with someone once, can I ever get it from them? i.e does frequency of sexual contact change the likelihood of transmission?

Theoretically, if you are exposed to HBV after sexual transmission and don’t get an infection, you are likely to have raise an antibody response to the virus, so your likelihood of getting an infection is lower. I would not count on this mechanism though. Better to make sure you’re vaccinated and use barrier protection where possible to reduce the risk.

Hope this helps,
Thomas