No one with an undetectable viral load transmitted HIV in the Partner Study
The second largest study to look at whether people with HIV become non-infectious if they are on antiretroviral therapy (ART) did not find cases where someone with a viral load below 200 copies / ml of HIV transmitted by anal or vaginal sex.
Statistical analysis showed that transmission via anal sex was more likely. And for someone undergoing successful HIV treatment it was 1% per year. And 4% for anal sex with ejaculation where the HIV-negative partner was passive.
However, the real probability is probably much closer to zero than that.
When asked what the study told us about the chance of someone with an undetectable viral load.
Speaker Alison Rodger said: "Our best estimate is that it is zero."
However, I, Claudio, would not feel calm like that! I would always and necessarily need the condom.
I even recognize that for me, it is already a “late modesty”.
Participants Had Undetectable Viral Load
Study HPTN 052, Undetectable Viral Load and HIV Transmission
In view of the fact that the previous study HPTN 052, established in 2011 that the effectiveness of antiretroviral therapy in reducing HIV transmission from the HIV-positive to the HIV-negative partner was at least 96% in heterosexual couples, but there were very few gay couples in the study to thereby establish whether the same applied to them (or instead of anal sex).
O PARTNER study was created to remedy this knowledge gap. And so far, he has recruited 1110 couples, where the partners have serodivergent status, and approximately 40% of them are gay couples. And I suggested you can take advantage and open this article in another tab: How Long Until You Start Passing HIV To Others?
To participate in this study, couples have to be doing sex without condom at least part of the time.
The HIV-negative partner must not be using pre- or post-exposure prophylaxis (PEP or PrEP).
And the HIV-positive partner has to be in Antiretroviral Therapy (ART), with the most recent viral load below 200 copies / ml.
This study is different from the HPTN052 that the effectiveness of HIV-positive partners initiating the therapy (versus partners who had not started).
In total, 767 couples participated in this two-year interim analysis and there were a total of 894 contraceptive follow-ups.
Among heterosexual couples, HIV status was divided into equal parts.
And in half of the couples the man had HIV and the other half, the woman.
Gay couples were having sex without a condom with an undetectable viral load
Some couples were excluded from the analysis. In most cases, this was because they did not show up at follow-up visits. But in 16% of cases, it was because the HIV-positive partner developed a viral load above 200 copies / ml.
And in 3% of cases because the HIV-negative partner took PEP or PrEP.
There were significant differences between gay couples and heterosexual couples. At the baseline, gay couples were having sex without a condom for a shorter average period:
1,5 years versus 2,5 for heterosexual men and 3,5 for women.
Heterosexual Hiv-negative Partners With Undetectable Viral Load Reported Having Have Vaginal Sex Without Condom, 72% With Ejaculation
During the follow-up period, all heterosexual HIV-negative partners reported having vaginal sex without a condom.
- 72% with ejaculation;
- 70% of HIV-negative gay partners reported passive anal sex,
- 40% with ejaculation,
- While 30% only reported being the active partner.
A significant proportion of heterosexual couples reported having had anal sex (it will be reported later).
In this way, sex without a condom outside of the relationship was much more common among gay men!
One third of HIV-negative partners reported this, versus 3-4% of heterosexuals.
There is no doubt that because of this, sexually transmitted infections (STIs) were much more common in gay couples.
And so, surprisingly, an index with 16% of gay men developing an STI (mostly gonorrhea or syphilis) during follow-up.
These figures versus 5% of heterosexuals.
The results of unprotected sex with undetectable viral load
The main news is that at PARTNER so far there have been no transmissions in couples with a partner with an undetectable viral load, in what was estimated to be 16.400 occasions of sex in gay men and 28.000 in heterosexuals.
Although some of the HIV-negative partners have become HIV-positive (the exact number will be revealed in a later analysis), genetic testing of HIV revealed that in all cases the virus came from someone other than the main partner.
Alison Rodger told the conference that if HIV-positive partners were not being treated in this group, 50-100 (average: 86) transmissions would have been expected in gay couples, and 15 transmissions in heterosexual couples.
Undetectable Viral Load and No transmission is not the same as zero chances of transmission
No transmission is not the same as zero chances of transmission. The researchers calculated the 95% confidence intervals for the observed results.
What this means is that they calculated the probabilities of zero transmissions to be the 'true' fact and what was the maximum transmission risk.
I give the results observed.
They established that there was a 95% chance that (in a couple where sexual activity is average for the studied group) the highest chance of transmission risk from a partner was 0,45% per year and anal sex of 1% per annum.
At a press conference, Dr. Jens Lundgren, principal investigator for the PARTNER study, stressed that this meant that there was a 5% maximum chance over a 10-year period.
One in 10 partners in a gay couple who had unprotected anal sex could acquire HIV;
Likewise, it was more likely that their chances of contracting HIV from their partners were very close to zero, and in fact could be zero.
Maximum likelihood of transmission of someone on HIV suppressive therapy at its highest degree was 2% per year
As the group the studied group becomes smaller, the greater the confidence intervals become and the certainty of a result becomes 'vague'.
This means that the maximum probability of chance of transmission of someone on HIV suppressive therapy to its greatest degree was 2% per year for anal sex with ejaculation.
2,5% for passive anal sex
And 4% for passive anal sex with ejaculation.
The latter data implies more than one in three chances of infection if sexual behavior remains unchanged for more than ten years, but again, this is one of the 'worst' scenarios and the likelihood is probably smaller.
Thus, no transmission occurred despite relatively high levels of STIs, especially in gay couples.
When the 'Swiss Statement' was released in 2008, it stated that people with an undetectable viral load did not transmit HIV.
However, he made an exception in people with STI: the PARTNER study may be telling us that STIs (in positive or negative partners) do not increase the likelihood of HIV transmission.
That is if the positive partner is on ART and undetectable (although, of course, it can still be transmitted to them).
Undetectable Viral Load Has Reduced Risks*
PARTNER is recruiting couples of gay men and, as noted above, its full result will not come out before 2017. Until then we need to be careful about what it has proved, and, as Jen Lundgren pointed out, it will never be possible to show with mathematical certainty that the risk of transmission to someone on successful HIV therapy is absolutely zero. In addition, these results exclude situations where ART has failed the HIV-positive partner, although there have been few of these cases.
Translation: Rodrigo Sgobbi Pellegrini
A personal note: CTRL + C CTRL + V
These results exclude situations where ART failed!
* The simple possibility, with all that has been said, written, published everywhere, even now, after years, I would feel prevented, both ethically and morally, from relating to someone without a condom just because I’m undetectable for over ten years, because the “ART could fail”!
I still remember how I felt with the result, the terror, the fear, the unknown. The “old problem of others”. If I close the acoustics of my Spirit to my own past, I cease to be who I am. It's surreal!
After the publication of this text there is more to be seen on this link and I advise you to read
The Rodger et al. HIV transmission risk through condomless fri IF HIV + partner on Supressive ART: PARTNER study. Conference on Retroviruses 21st and Opportunistic Infections, Boston, abstract 153LB, 2014.