As shown in Fig. 1a, consistent with our previous results, all four SIVcpz strains replicated at high levels from the acute to the chronic stage of infection and had similar pVL kinetics to HIV-1, regardless of whether they were derived from Ptt (SIVcpzMT145) or Pts (SIVcpzBF1167) chimpanzees. Here, PTS is linked to infection.