Can someone please explain frenzy

I understand the basic idea of frenzy with the armor and antivirus to cure it. What I don't fully understand is if attacking cures it, once cured does the frenzy come back or is it permanently gone for the rest of that fight and I just get an affinity bonus for the rest of the fight, or does it come back after a while. And if it does come back does the buff go away or stay? and is the buff permanent or only for a certain amount of time?