You have to have good training partners and not people who crank on things. There's a difference between cranking on it and catching it, holding it and making the guy work out. You have to be selective with your training partners for sure.
The nature of a protective immune response to HIV is still unclear. Because in a very, very unique manner, unlike virtually any other microbe with which we're familiar, the HIV virus has evolved in a way that the immune system finds it very difficult, if not impossible, to deal with the virus.