Prospects for Prevention of and Early Intervention Against HIV

THE IMMUNE response that develops subsequent to infection with human immunodeficiency virus (HIV) consists of both humoral and cellular elements that, when assessed in vitro, can inhibit virus infection and lyse virus-infected target cells. If such activities were operative in vivo, one would expect that they would suppress virus replication and virus-induced cytopathic effects. The antiviral immune response may thus represent one of the primary host defense mechanisms responsible for the protracted asymptomatic phase of the disease, which, in most patients, can last several years. An important question to be answered for development of vaccine strategies against HIV is whether this response might be an effective barrier to HIV infection de novo. If the immune response can indeed control the virus even for a limited period, then the issue would not be whether it is possible to mount a protective immune response against HIV, but whether it may be necessary