CD4 and infection: Correlating with these two pathways of entry MNPs can transfer HIV to CD4 T cells in two successive phases.31,38Trans-infection, (also called first-phase transfer) occurs when the MNP interacts with a CD4 T cell within 2–6 h, where virions are either held on the surface of the MNP39,40 or discharged from VCCs in a pulsatile fashion.41 This most likely occurs in the tissues where transmission takes place.