Undetectable Viral Load+Dating/Safe Sex

Hi friends!

New here but very very grateful to have found this space! I am very confused and could use some guidance from people who seem to have much more knowledge about all of this than me. Apologies because this will be long.

Background info:

So I am a mid 20’s male, adopted from Asia as a baby, raised in the US. I was diagnosed about 4 years ago, found out by almost completely accident. I’m gay and was deciding to go on Truvada once a day for PrEP (which coincidentally contains tenofovir, for those unfamiliar, thus treating my Hep B). I had never been tested for hep b before in my life, just vaccinated when I started going to school here and my PCP told me that she thought I should get checked for it because my liver enzymes were elevated and there was no record of me ever being tested. Nasty shock for me and my adoptive parents to find out. The doctors said based on my lab work, it was most likely that I contracted hep b as a baby, given high transmission rates in Asia and a lack of testing I received in Alabama when I was brought to the US.

The good news though is that every lab test I’ve ever had for hep b has been exceedingly normal. My viral load is undetectable and has been since the first set of labs I got 4 years ago (<10 IU/mL). I feel like I’ve had a lot of time to make peace with the diagnosis in terms of having Hep B and that being a part of my healthcare.

My question/confusion though, pertains to the dating and sex part of the equation. I feel like I have received some mixed and confusing messaging around what to tell prospective partners and even what the varying risk levels are of different activities. And I always get so nervous and embarrassed asking these questions face to face with a doctor so I’m hoping that in typing it all out (even if it’s cringey), somebody in this community will be able to help me figure this out.

Basically my understanding is that while it’s really good that my viral load is undetectable and will certainly make transmission unlikely, there isn’t enough research to know for absolute sure if u=u for hep b as it does for HIV. And so generally, the recommendation is to use a barrier (ie, condom, dental dam, etc) if you don’t know the other partners vaccination/immunity status? But I had also previously been under the impression that if the other partner either had been vaccinated as a baby and confirms immunity/antibody titer, or was boosted/vaccinated recently, then it was possible to safely forego the condom, as I wouldn’t be able to transmit the virus at that point. That was what I thought I had been told at least.

What I usually tell guys on apps or in person is a long text that essentially contains 5 pieces of info:

  1. I have Hep B, which I got as a child, but I’m on medication for it so viral load is undetectable
  2. But they don’t have enough research to know for sure if that means untransmittable
  3. Good news is many people have been vaccinated for it for school, or work or what have you at this point, which makes them immune
  4. They’re also supposed to check you for immunity before you go on PrEP
  5. But they recommend using condoms unless you confirm the partners immunity status, just for complete safety

Some guys are overwhelmed and have never even heard of it before. Some guys are familiar with it and don’t wanna fuck w it. Some guys are fine with using condoms. And of course there are other dudes who know they’ve been vaccinated and want to have unprotected sex. For anyone who is not a part of specifically the gay male community, with the prevalence of PrEP in the community over the last 5 years or so, unprotected sex has become MUCH more common. And I would be lying if I said I had not been partaking (not sure if this is too much information, but I have exclusively been the receptive partner or “bottom”) with guys who had been vaccinated, been boosted and/or tested for immunity, because I was under the impression and was telling them that was safe….

Cut to two days ago, I’m having an appointment with a different infectious disease doctor and they are saying that the vaccine is incredibly effective and lowers risk to very close to or basically 0… but it’s not actually 0 as I’d thought. I later emailed them to clarify this exact question (ie, can the condom be safely foregone if the other partner has been vaccinated). They said the vaccine was very effective and though they still recommend condoms to protect from other STIs, “the risk of HBV transmission to a vaccinated partner is extremely low”. Which still isn’t saying that it’s a zero chance or that it’s safe. So it seems that they are advocating for an approach of using barriers for everything all the time? Which I know is technically public health sexual guidance anyway but in practice, I know few people who regularly use protection for oral sex. And having done oral with protection before, it’s a hard sell for most guys.

But I also don’t know if this is just sorta doctor/science/public health speak for “functionally zero chance” of transmission or what, as I know many professionals like to err on the side of caution unless they can say with absolute confidence. And this leaves me at a hard place for what I tell guys. If the best answer medicine and science can give is “it’s an extremely low chance” or “very unlikely” but not zero… then does every guy I potentially have some form of unprotected sexual contact with (even just oral) need to have a hep b panel after we hookup? Even if someone was comfortable with the “low chance” and wanted to proceed with unprotected contact, I feel like they’d still wanna have some way of making sure they’re all good after the fact. Which maybe is why the doctor is recommending the condoms for everything then?

Now I’m just sorta a confused and anxious mess. The TLDR is basically:

  1. Given my undetectable status, if I’m with a partner who is vaccinated for hep b, is any amount of sexual contact safe without barriers or should there always be a condom involved?
  2. What should I be telling prospective partners?
  3. If unprotected sex turns out to in fact not be safe, as it’s seeming like it is, do I need to attempt to track down all former unprotected partners? What do I even tell them to do? Just get tested for hep b? And “sorry I told you we’d be fine but turns out I misunderstood information”?

Ultimately, if the answer is yes, I must use a condom for everything and if eventually I have a long term partner who is comfortable risking it, then we can see, then that is fine. I just sorta want a more firm answer lol.

Definitely struggling with some low morale at the moment, and just general frustration at the situation. Hope everyone else is doing okay :heart:

Any help is MUCH appreciated! (Please don’t hesitate if you need more of my lab work info to get more context, didn’t really know what was needed for this).


Dear @Monkeiiboy,

Thank you for sharing your story and highlighting an important issue: where the scientific/academic meet the reality of human relationships.

First of all, good on you for being informed and empowered enough to provide that information to potential partners. I’m super impressed and can see how that can be quite a big responsibility to take.

This is my impression too, given that this is generally the advice given to relationships where people are trying for a pregnancy and the male is HBV-positive (though vaginal transmission in general seems to be lower than anal transmission).

There are multiple aspects that may relieve your conscience:

  • Being a bottom, you are less likely to transmit compared to being a top.
  • Scientists and clinicians will generally be quite conservative in these cases. This makes sense legally and ethically speaking; there is power in words when you are a trusted expert, and one doesn’t want to wield them incorrectly.
  • Just to provide some context of transmission risk: see figure 2 in this WHO report https://apps.who.int/iris/bitstream/handle/10665/333391/9789240002708-eng.pdf. It shows that in high fluid exchange setting (birth of a child), maternal virus levels less than 20000 do not result in a chronic infection in newborns, who are very highly susceptible to chronic infection. Of course, it needs to be added that the newborns are vaccinated straight away and given HBIg (this prevents infection in 75-90% of cases, without antivirals).
  • Another study (Multiple HBV transfusion transmissions from undetected occult infections: revising the minimal infectious dose | Gut) has looked at the minimum infectious dose in the setting of blood transfusion from people who are have undetected HBV DNA (<10IU/mL). They found that the minimum infectious dose could be between 100-16 copies (16 copies = 3IU) in “susceptible recipients non-immune to HBV”. This means you’d need on the order of a third of a mL of fluid transfer directly administered to the blood, probably unlikely with micro-tears associated with sex (happy to be corrected on this though). A comment to this paper also talks about high variability in the infectiousness dose - New minimum infectious level of hepatitis B virus proposed and continued testing for HBsAg questioned - McCullough - Annals of Blood.
  • Adults exposed to HBV are highly likely to clear it (90%, even without vaccination) and not have a chronic infection, though there is a risk of acute hepatitis.

In the end, it really depends on how you define “safe”, which I suspect this is different for everyone.
Unfortunately, I don’t think there are clear answers to your questions. It is true there is not enough evidence provided for many doctors or scientists to be comfortable with saying you’re completely safe.

I would be keen to hear perspectives from @HealthExperts here.

Hope this helps a bit,

I have heard that they are finding PrEP to also be effective in preventing HBV infections. A google search will bring up the information.

Dear @Monkeiiboy

I am an Infectious Diseases specialist and virologist and agree with what Thomas said.
As scientists/doctors we almost never give “100%” certainty with anything.
This is part of the scientific mindset as we realise that unpredictable things can and occasionally do happen. For instance can we be 100% certain the earth won’t be destroyed this week by some unexpected cosmic event? EXTREMELY unlikely but not something we can be 100% certain about. Clinical medicine is even more uncertain as there are so many human variables.

In practice, if someone os on treatment and has a very low or undetectable virus load the risk of transmission to anyone else (in any setting) is extremely low, perhaps zero. We know this reduces the risk of transmission from mother to baby and also in health care settings (e.g. surgeons with hepatitis B are allowed to operate and perform 'exposure prone procedures" if their HBV DNA is < 200 IU/mL).

On the other side, if someone is fully vaccinated against hepatitis B and has confirmed immunity/antibodies then the risk of them contracting hepatitis B is extremely low, perhaps zero. Therefore the risk of someone on treatment with an undetectable virus load transmitting to someone who has been vaccinated with confirmed immunity is even lower, perhaps zero.

Therefore I would not recommend a need for using condoms in that setting to prevent HBV transmission, although of course they can help reduce the risk of other STIs (including HIV).
It sounds like you are doing all the right things (and are commendably responsible compared to many others!) so no need to do more.

However there are always uncertainties in life, so we can never say never. It is almost impossible to do perfect large scientific studies for this kind of situation as this would require thousands of volunteers who are prepared to expose themselves to virus in a controlled situation to test all possible variations. Even then you would only have only tested thousands. Do you need millions to be sure? We have a large amount of evidence from observational studies that provide high levels of confidence for our statements and recommendations but it is not perfect.

For instance, people can sometimes have “blips” in their virus load, so just because it was undetectable a month ago or a week ago does not necessarily mean it will be undetectable today. Or that there was not some technical problem with the last lab test and it was incorrect. And just because the virus is “undetectable” does not mean there is NO virus there, just that any virus is at such low levels we can’t detect it with current (extremely sensitive) tests. Conversely for someone who has been vaccinated and/or boosted do you know for sure that they had a good antibody response? How recently was it checked? Was the test correct? Are you sure it wasn’t mixed up with someone else’s test? Are they telling the truth? Is it possible they have some rare immune deficiency that makes them more susceptible to hepatitis B despite a good vaccine response and antibody level?

I don’t say all that to make you feel anxious or uncertain, just to give some context for why doctors are usually very reluctant to say “100%”. We have almost all been caught out at some time by a situation or outcome that was unexpected, often due to incorrect information or a “random” variable we were unaware of.

So thank you for sharing your story and bringing up this really important topic.
Keep up the good work and follow your doctors’ recommendations, but hopefully this will help to explain why they are reluctant to give you “100%” certainty for this (or anything else).

Best wishes

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Thank you, @ThomasTu and @MarkDouglas, for your detailed explanation and clarifications. Thank you, @Monkeiiboy, for bringing attentiont to this important and sensitive topic that I have struggled with as well.

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