- Viremic controllers and elite controllers/suppressors maintain control over HIV-1 replication. Some studies have suggested that control is a result of infection with a defective viral strain, while others suggested host immune factors have a key role. Here we document two HIV-1 transmission pairs: one consisting of a patient with progressive disease and an individual who became an elite suppressor, and the second consisting of a patient with progressive disease and a viremic controller. In contrast to another elite suppressor transmission pair, virus isolated from all patients was fully competent. These data suggest that some viremic controllers and elite suppressors are infected with HIV-1 isolates that replicate vigorously in vitro and are able to cause progressive disease in vivo. These data suggest that host factors have a dominant role in the control of HIV-1 infection, thus it may be possible to control fully pathogenic HIV-1 isolates with therapeutic vaccination.