So I recently learned about these 2 studies with serodiscordant couples with the HIV virus having condomless sex. The HIV positive partner had a viral load under 200. There was 58,000 sexual acts (22,000 homosexual) and ZERO transmission of the HIV virus. The study had in total 11 transmissions of HIV (10 are gay men). 8 of the 11 reported having sex outside of the relationship but none of the 11 is linked to the partner. The PARTNER 2 study results will be released in 2019 with regards to MSM. It is still recommended to serodiscordant couples use condoms if you are gay. However, at a low viral level the actual transmittance of HIV is highly unlikely even without a condom. Viral blips weren't shown to become high enough to transmit the virus but it is still possible to occur. The confidence interval is 95%. The viral level necessary in order to transmit HIV is unknown. But pretty positive news for those that have HIV that is treated worrying about transmitting it to partners as well as discrimination against HIV people for things like spitting or bitting if they have a less than 200 viral load. https://www.poz.com/article/publish...gs-stress-power-hiv-meds-prevent-transmission
Two years might seem like a long time, but when you take into account periods on the order of decades, then the picture might not be so rosy. But, whatever the results, ARV meds are very effective at reducing transmission of the virus. One other thing to note is that the HIV+ individual has to take the meds on a regular basis and that can be a problem with certain people.
Thats why the PARTNER 2 study is coming out. But yes adherence to medication is very important for treatment to be effective as prevention! It still very good news. People in this situation should still wear condoms.