Examples of treatment of viral infections Principles of Therapy of Hiv infection HIV infection is always harmful Ongoing HIV replication leads to progressive immune system damage and ultimately to AIDS True long-term disease-free survival is unusual The major factor limiting the ability of antiretroviral drugs to control HIV replication and delay disease progression is the development of resistance The selection of resistant Hiv variants is limited by potent combination therapy that suppresses HIV replication below the limit of detection The goal of therapy is therefore the maximum achievable suppression of HIV replication Combination treatment is required HAART- highly active anti-retroviral therapy