Developing animal models for AIDS research--progress and problems.

Tremendous advances in our understanding of the human immunodeficiency viruses (HIVs) have been made through the use of animal models. However, there are limitations inherent in many of the current models that use either nonhuman primates, or viruses other than HIV-1. Researchers continue to search for improved models using small-animal model alternatives and different viruses. Animal models will remain an important tool in our continued search for vaccines and therapeutic agents.