Link between the X4 phenotype in human immunodeficiency virus type 1-infected mothers and their children, despite the early presence of R5 in the child.

Coreceptor use was determined for human immunodeficiency virus type 1 (HIV-1) isolates of various subtypes from 11 women during pregnancy and their infected children. Isolates from peripheral blood mononuclear cells (n=79) and from plasma (n=59) were available. The clinical and immunological stages of HIV-1 infection were recorded.