It's a great question, and it's one of the notes that I made at the meeting to see if we can quantify how many allies are out there withholding blood from the system. I don't have an answer for you yet, but it's a question that is an open question.
Again, as a community, as a country—and this came up in the scientific discourse—we have two choices. We can have an infallible screen that applies to everybody, regardless of behavioural factors, and that is about the science and about testing what's in the blood; or we can have a system that first imposes a behavioural screen.
Where we are now is that we have a process that imposes a behavioural screen, and the choice that CBS and Héma-Québec have made is that a one-year period, where a man does not have sex with another man, satisfies their criteria for safe behavioural practices to then allow that blood into the system.
Does the science bear a difference between a two-month deferral, a six-month deferral, a one-year deferral? Many scientists will tell you no, and they did so at the conference. That is why it's important for the research that comes out of this conference to show us what the behavioural risks really are.