Replicative capacity of human immunodeficiency virus type 1 transmitted from mother to child is associated with pediatric disease progression rate.

Human immunodeficiency virus (HIV)-infected infants in the developing world typically progress to AIDS or death within the first 2 years of life. However, a minority progress relatively slowly. This study addresses the potential contribution of viral factors to HIV disease progression in eight infants selected from a well-characterized cohort of C clade HIV-infected infants, monitored prospectively from birth in Durban, South Africa. Three infants were defined as “progressors,” and five were defined as “slow progressors.” We observed that slow-progressor infants carry HIV isolates with significantly lower replicative capacity compared to virus from progressors. Furthermore, our data suggest a link between the attenuated viral phenotype and HLA-B* 57/5801 epitope-specific Gag mutational patterns of the transmitted virus and not to coreceptor usage or to the presence of Nef deletions or insertions. These data underline the importance of virus-host interactions and highlight the contribution of viral attenuation through Gag-specific CD8+ T-cell escape mutations, among other factors, in the control of pediatric HIV infection.