It is proposed that specific human immunodeficiency virus determinants in seropositive individuals are capable of evoking very strong suppressor T cell responses which inactivate certain helper T cells. This helper T cell suppression may be sufficient to inhibit the cytotoxic T cell recognition of these specific retroviral antigens and significantly reduce neutralizing antibody titers. As a consequence of the poor T helper cell responses to these different antigens, a number of related human immunodeficiency virus isolates are able to escape immune surveillance over the entire course of the infection. The selection and persistence of these distinct but related viral isolates may allow the human immunodeficiency virus infection to progress to other tissues and contribute to the gradual destruction of the remaining helper T cell population. Thus, the development of an effective antiviral therapy and possibly even a cure for the acquired immune deficiency syndrome may depend on the management of the suppressor and helper T cell activity in the infected individual.