Methods

LPV/r+ ZDV+ 3TC was commenced either immediately (in 250 of 252 children randomized in arms 2 and 3) or at clinical/immunological progression (103 of 125 children in arm 1). Interruption of ART occurred after 40 (arm 2) or 96 weeks (arm 3) and re‐initiation with LPV/r+ ZDV+ 3TC was based on immunologic/clinical criteria. Viral load was measured on all children with a stored specimen at their last visit, having been on initial or restarted ART following interruption (arms 2 and 3) for at least 24 weeks. Children in arms 1, 2 and 3 not initiating ART due to death (16, 0, 0), LTFU (2, 2, 0) or other reason (4, 0, 0) are excluded. Resistance testing was performed on samples with a viral load (VL)≥ 1000 c/mL together with the matched baseline sample, if available. Reverse transcriptase (NRTI and NNRTI) and PI inhibitor mutations were analyzed using a validated in‐house population‐based sequencing assay and the IAS 2011 mutation list.