Human immunodeficiency viruses and drug therapy: resistance and implications for antiretroviral therapy.

Through a concerted effort to combat the human immunodeficiency virus (HIV) epidemic, researchers have made significant strides in molecular biology, virology, and immunology, which have resulted in an increased understanding of the complexities of this infection. The biggest obstacle to the success of current HIV therapy, however, is the emergence of viral resistance. Viral resistance is caused by mutations in the HIV-1 genome coding for structural changes in the target enzymes that can affect the binding or activity of the inhibitors. More information on the genetic basis of HIV resistance, mechanisms of viral variation, and therapeutic strategies for overcoming HIV resistance are needed. Sixty million people have been infected with HIV, 24 million have died, and it is projected that 200 million individuals will be infected by 2020.