Undetectable = Untransmittable
WHAT DOES UNDETECTABLE MEAN?
A viral load test will be able to show how much HIV is present in the blood.
The goal of HIV Treatment is to get the levels down to ‘undetectable’. This does not mean that the HIV is gone, it means that the amount of HIV cannot be detected using current tests. The results are given per millilitre of blood and generally speaking, if the results are undetectable, this means that there are fewer than 50, 40 or sometimes 20, copies per ml.
Basically, the levels of HIV are so low, that they can no longer cause any damage to the body, and HIV will not be transmitted through sexual contact.
An undetectable viral load does not protect against acquiring or passing on other sexually transmitted infections or prevent pregnancy, so using a condom is still advisable in some situations, but for HIV the science is clear –
UNDETECTABLE = UNTRANSMITTABLE