In this guide, you will learn about the basics of HIV, how it harms the immune system inside the body, and how a mix of anti-HIV drugs can slow its progression. This guide will define viral load and CD4+ cell counts, explaining how and why they are used to predict what HIV disease will be like for an infected child. Descriptions of anti-HIV drugs - both newly approved and those still in clinical trials - are included. This guide is about HIV infection and anti-HIV drugs for children. As with any medical therapy, the decision to begin or change treatment should be made after discussions with trusted health care professionals who know about children and HIV.