Combining Drug and Immune Therapy: A Potential Solution to Drug Resistance and Challenges of HIV Vaccines?

According to the World Health Organization's 2007 estimates, close to 33 million people worldwide are living with HIV/AIDS. Over the past two decades, significant progress has been made in understanding HIV pathogenesis and disease progression, which has allowed the identification of a multitude of drug and vaccine targets. Although currently available drug therapies have greatly increased the time from HIV infection to development of AIDS, drug resistance is an inevitable consequence that limits the duration of successful treatment. Consequently, a preventative vaccine remains the top priority; however, no vaccine trial performed to date has shown efficacy in human trials. Therefore, we must use all of our current resources in new creative therapies and strive to develop new methods to reduce persistent viral levels until an effective preventative vaccine is developed. One possible strategy is to use therapeutic vaccination or immune modulators to augment the immune response while antiretroviral chemotherapy limits viral replication. This combination approach is being utilized with success in the treatment of Hepatitis B infections and several trials have been completed and others are ongoing to determine the potential of combination immunological and chemical therapies for HIV infection. We will review the progress to date of anti-HIV drugs, preventative vaccines, and therapeutic vaccines and discuss the future strategies of combination drug and vaccine therapeutic strategies in the fight against HIV.