The occurrence of viral control after interruption of an antiretroviral treatment (ART) initiated during primary HIV-1 infection (PHI) is rare and the frequency and predictive factors of such a control are unknown.

Within the French ANRS PRIMO Cohort, 164 patients interrupted ART initiated during PHI. We compared patients whose viral load (VL) remained undetectable (<50 copies/ml) or low (50–500 copies/ml) 1 year after ART interruption to those who evidenced a rapid viral rebound.

After ART interruption, VL remained undetectable for a median time of 4.5 years in 14 patients (‘post-ART controllers') and low in another 14 patients for a median time of 1.5 years. Post-ART controllers also maintained higher CD4⁺ T-cell counts compared to other patients. Female gender, a high CD4⁺ T-cell count and low VL during PHI, and a high CD4⁺ T-cell count and low HIV DNA levels at interruption, were associated with post-ART HIV control. Treatment characteristics did not differ between controllers and non-controllers. Post-ART controllers had lower specific CD8⁺ T-cell frequencies and CD8⁺ T-cell activation on ART and after ART interruption than non-controllers.

Few patients maintain very low VL after interruption of treatment initiated during PHI. Early patient characteristics were the main factors of viral control, although early initiation of ART and the effect of ART on reservoir might contribute to control.