I am very puzzled by the fact that young people are getting infected again. They don't take precautions despite an enormous amount of information. It's like riding a race car at 200 kilometers an hour...
It's easier to learn things for life by the age of 12 and not the age of 18. This is just my guess.
One could not have isolated this retrovirus without knowledge of other retroviruses, that's obvious. But I believe we have answered the criteria of isolation.