1. A method for identifying a drug effective against mutant HIV protease, comprising: (i) providing a nucleic acid comprising mutant HIV protease comprising at least one mutation chosen from R41S, R41T, R41I, R41G and K70E as compared to the wild-type HIV strain IIIB/LAI; (ii) recombining said nucleic acid comprising mutant HIV protease of step (i) into a proviral nucleic acid deleted for said nucleic acid to generate a recombinant HIV virus; (iii) determining a phenotypic response to said drug for said HIV recombinant virus; and (iv) identifying a drug effective against mutant HIV based on the phenotypic response of step (iii).