Developments in preclinical AIDS vaccine efficacy models

Animal lentivirus systems have provided important models for evaluation and optimization of experimental immunization procedures that can be applied to the development of human AIDS vaccines. The following review summarizes recent key developments in the design of these animal lentivirus systems and results in animal lentivirus vaccine trials that have important implications for human AIDS vaccine. The focus of this review is not to provide an exhaustive summary of animal lentivirus trials, but rather to identify the new themes in AIDS vaccine development that have evolved from recent animal lentivirus vaccine trials. Thus, the following sections describe experimental results from nonhuman primate (NHP) lentivirus systems, simian/human immunodeficiency virus (SHIV) and SIV, and from non-primate animal lentiviruses, equine infectious anemia virus (EIAV) and feline immunodeficiency virus (FIV). These studies include optimization of challenge viruses, evaluation of mucosal immune responses to vaccines and protection from mucosal challenge, and the search for immune correlates of vaccine protection.