Virological rebound. Virological rebound after 4 weeks (top), 8 weeks (middle) and 24 weeks (bottom) from therapy interruption for two groups: very early (green boxes) that started HAART before seroconversion and late (blue boxes) that started HAART during chronic phase of primary HIV-1 infection. Filled boxes represent in silico data (resulting from three thousands runs) whereas empty boxes correspond to in vivo data. We have calculated the Mann-Whitney U test statistics for assessing whether the two independent samples (in silico and in vivo) come from the same distribution. In all cases we did not find a significant difference (P ≥ 0.05, Mann-Whitney U two-tailed test). Black lines indicate standard deviations. Information on parameter settings for the simulations can be found in the Additional file 1.