The timing of treatment with NA inhibitors is paramount, as early therapy is directly related to improved survival [66, [83] [84] [85] . The greatest level of protection was seen if the NA inhibitors were started within 48 hours of infection, and protection rapidly dropped after 60 hours [78, 79] . These initial studies, however, were performed with seasonal human influenza A and B, where the period of viral shedding is approximately 48 to 72 hours. In HPAI H5N1 cases from Southeast Asia, survival appeared to be improved in patients who received oseltamavir earlier (4.5 days versus 9 days after onset of symptoms) [66] . Both of these time periods are much longer than documented in animal models, so the window of optimal therapy is still unknown, particularly if viral shedding exceeds the average 48 to 72 hour period seen in seasonal influenza A and B infections.