Our finding of a 5% risk of severe neutropenia among infants is similar to that of the MASHI study in Botswana, in which prevalence of severe neutropenia among 69 breastfed infants aged 2–7 months whose mothers received ART was 5.9%.7 Unlike the MASHI study, in which women were started on ART at CD4+ cell counts below 200 cells/mm−3, women in our study initiated ART at higher CD4+ cell counts (>350 mm−3). The gene discussed is CD4; the disease is Decreased total neutrophil count.