Table 1. DAS181 inhibits pandemic IFV A(H1N1): Number of Viral Foci in MDCK culture (per well).

Virus	PBS	DAS181 0.04 µM	DAS181 0.16 µM	DAS181 0.63 µM	DAS181 2.5 µM	DAS181 10 µM
A/Mexico/4604/2009	80±9	1±0	0	0	0	0
A/California/04/2009	180±15	3±1	1±0	0	0	0
A/Hawaii/31/2007	20±6	5±1	2±1	0	0	0
A/Hawaii/21/2007 (H274Y)	26±4	0	0	0	0	0

MDCK cells were pretreated with DAS181 for 2 hours (at indicated concentrations) before infection with A/Mexico/4604/2009, A/California/04/2009, or seasonal influenzas A/Hawaii/31/2007 or A/Hawaii/21/2007 (oseltamivir-resistant H274Y mutant) at M.O.I. ranging from 0.001 to 0.005 MOI. At 24 hrs p.i. the cells were immunostained to detect NP viral antigen and the number of positive foci per individual well was counted (“Number of Viral Foci”). Simultaneously the viral yield in the culture supernatants (media above the cell monolayers) collected from individual well was determined (Table 2). Values represent mean±SD of quadruplicate experiments.