Human rIL-2 does not affect viral load . Four Rhesus macaques were infected with the pathogenic SIVmac251 strain and then treated during chronic phase with human rIL-2 (low dose: О,Δ or high dose: ●,▴). Each symbol represents one monkey. Viral load (copies/ml) was quantified by RT-PCR at the day of treatment and thereafter. Euthanasia date is represented.