A PROPOSAL FOR A NEW APPROACH TO A PREVENTIVE VACCINE AGAINST HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1

Human immunodeficiency virus type 1 (HIV-1) is a more complex retrovir us, coding for several accessory proteins in addition to the structura l proteins (Gag, Pol, and Env) that are found in all retroviruses. Mor e complex retroviruses have not been isolated from birds, and simpler retroviruses have not been isolated from humans. However, the provirus es of many endogenous simpler retroviruses are present in the human ge nome. These observations suggest that humans can mount a successful pr otective response against simpler retroviruses, whereas birds cannot. Thus, humans might be able to mount a successful protective response t o infection with a simpler HIV-1. As a model, a simpler bovine leukemi a virus which is capable of replicating has been constructed; a simple r HIV-1 could be constructed in a similar fashion. I suggest that such a simpler HIV-1 would be a safe and effective vaccine against HIV-1.