Figure 8: Both WT and mutant B/Brisbane/60/2008 viruses are sensitive to 46B8 in vivo and to Tamiflu.

(a) MDCK cells were infected with WT or mutant viruses at MOI 0.01. After removal of the virus inoculum, cells were grown in the presence of varying concentrations of oseltamivir acid for 4 days. Released viral genome in the supernatant was quantitated by qPCR of the viral M1 Matrix gene. The copy numbers of each virus were normalized to the value at the lowest oseltamivir acid concentration. The assay was done in triplicate. (b) DBA/2 J mice were infected intranasally with a minimum lethal dose of the WT or mutant viruses. At 48 h post infection, mice received Tamiflu orally at 100 mg kg⁻¹ twice a day for 5 days. Survival curves are shown. Each group contains eight mice. Log-rank tests of Tamiflu versus water treated groups for all viruses give P<0.05. (c) DBA/2 J mice were infected intranasally with a minimum lethal dose of the WT or mutant B/Brisbane/60/2008 viruses. At 72 h post infection, mice received a single treatment of 46B8 or a control IgG intravenously at 15 mg kg⁻¹. Survival curves are shown. Each group contains eight mice. Log-rank tests of 46B8 versus control IgG-treated groups for all viruses give P<0.05. (a: mean and s.e.m.)