A wagering game system and its operations are described. A disposable nozzle mountable on a holder extending outwardly from the front discharge end of the barrel provides an indication that the nozzle has been used and should be discarded. A method for adaptive control of such a mixed-signal integrated circuit is also provided. Preferably, xenoantigen vaccination is followed by boosting with autoantigen PAP from the same animal species as the mammal being treated.