The R5broad phenotype is predictive of early immunological failure in children. Categories are defined according to the Centers for Disease Controls : CDC 3 = severe immune suppression. Narrow and broad refer to viruses with R5 phenotype detected at or close to birth. Viruses able to exclusively use wild type CCR5 receptor are defined narrow, whereas those using chimeric receptors besides the wild type CCR5 are defined broad. Statistical analysis was performed to detect the influence of the virus with R5broad phenotype on disease progression of the children; p = 0.0218 (Pearson’s chi Square).