Just for absolute clarity...
We need to be undetectable for at LEAST SIX MONTHS before we are Un-infectious.
Why?
This is because the level of the HIV virus in our blood drops to undetectable faster than it does in other bodily fluids.
These other fluids include semen, pre-ejaculate fluid (pre-cum), vaginal fluid and rectal fluid (rectal fluid is the mucus that lines the rectum).
Because it takes longer to get the virus down to undetectable levels in these fluids we are not Un-infectious for the additional six months.
It is important that we all understand this point.
I hope this helps,
As Always,
Kind Regards,
Paul.