Chang explains that under the old regulations new drugs had only to demonstrate that they reduced the amount of HIV in the blood (viral load) to receive approval. When this resulted in a plethora of new drugs, the department decided that it was time for more stringent regulations. The new trial regime requires that new drugs reduce the viral load to under 50 copies per milliliter.
張念原解釋，舊法規定只要新藥能降低臨床試驗病人的血中 HIV 病毒濃度，就可通過審查；但眼見近年各式愛滋新藥紛紛出籠，所以新法趨於嚴格，要求每 c.c. 血液中的病毒數必須少於 50 顆。