A theory just popped into my mind, and I'm in a rush, so can't check through the posts to see if someone has already posted this.....
I think that
Tanya could have been bitten by the slow turner that she was experimenting on way back when. It could have happened at a time when she was the only person looking at him, and he went a bit rabid for a short time, and managed to bite her.
And when she said that she experimented some drugs on a slow turner, she could have meant herself, and found that some worked, but they were extremely limited in amount, so didn't mention it to anyone.
Any similar feelings?