She explained how plasma and breast milk were collected from the 33 women in the trial at 2, 8, 16, and 20 weeks.Both were assayed for viral load and resistance mutations to NVP.

• 解释如何收集33名妇女的血浆和母乳（收集时间在试验的第2, 8, 16, 和20周）与分析病毒量和对NVP的限制性突变。