Table 4.

IC50 (μM) values of reference compounds tested against different influenza strains using the assay for detection of (A) inhibitors of any stage of the virus life cycle and (B) blocking activity of anti-influenza antibodies. For A/WSN/33, VX787 and Ribavirin show similar IC50 values under both assay conditions, while Oseltamivir’s IC50 is 10 times higher when tested in the assay to assess the potency of antibodies for blocking the virus entry. Oseltamivir potency could not be determined for the rest of the strains in the concentration range used in the assay for detection of the blocking activity of antibodies. Results in Table A are the average of at least 7 determinations.

A. Influenza strain	VX-787	Ribavirin	Oseltamivir
A/WSN/33, H1N1	0.008	33.72	0.04
A/Udorn/72, H3N2	0.01	33.18	0.07
B. Influenza strain	VX-787	Ribavirin	Oseltamivir
A/WSN/33, H1N1	0.0037	33.2	0.135
A/Brisbane/10/07, H3N2	0.013	64.67	>0.5
A/mallard/Netherlands/12/00, H7N7	0.0049	43.55	>0.5
B/Bris/60/2008, Victoria lineage	>0.04	9.69	>0.5
B/Florida/4/2006, Yamagata lineage	>0.04	2.69	>0.5