TABLE 1

NHC efficacy against a panel of influenza virus and RSV isolatesa

Viral strainAssay method, host systemEC50 (μM) (95% confidence interval)SIOrigin
A/WSN/33 (H1N1)Plaque assay, MDCK cells3.1 (2.25–3.82)98Human
A/WSN/33 (H1N1)TCID50-HA assay, MDCK cells1.1 (0.86–1.22)275Human
A/California/7/2009 (H1N1) pdm09TCID50-HA assay, MDCK cells3.1 (1.49–6.23)98Human pdm09
A/Georgia/M5081/2012 (H1N1)TCID50-HA assay, MDCK cells3.4 (2.92–3.9)89Human pdm09
A/Netherlands/602/2009 (H1N1) pdm09TCID50-HA assay, MDCK cells1.8 (1.17–2.55)171Human pdm09
A/duck/Alberta/35/76 (H1N1)HA assay, in ovo0.6 (0.45–0.48)NAAvian
A/swine/Spain/53207/2004 (H1N1)HA assay, in ovo0.1 (0.02–0.12)NASwine; Eurasian avian-like
A/chicken/Potsdam/178-4/83 (H2N2)HA assay, in ovo0.4 (0.15–1.35)NAAvian
A/Vietnam/1203/2004 (H5N1)TCID50, MDCK cells0.142,143Avian
A/Anhui/1/2013 (H7N9)TCID50, MDCK cells0.132,308Avian
A/Aichi/2/68 (H3N2)TCID50-HA assay, MDCK cells3.2 (2.68–3.88)93Human
A/Wisconsin/67/2005 (H3N2)TCID50-HA assay, MDCK cells1.7 (1.27–2.33)182Human
A/Panama/2007/99 (H3N2)TCID50-HA assay, MDCK cells1.2 (0.05–2.0)250Human
A/swine/Ohio/sw10-132/2010 (H3N2)TCID50-HA assay, MDCK cells3.2 (2.52–4.05)95Swine; triple-reassortant lineage
B/Yamagata/16/88TCID50, MDCK cells0.015 (0.011–0.019)20,000Human
B/Brisbane/60/08TCID50, MDCK cells0.006 (0.003–0.008)50,000Human
recRSV-A2-L19FReporter assay, HEp-2 cells3.7 (2.8–4.9)74Human
RSV clinical strain 5S9Plaque assay, HEp-2 cells0.69 (0.5–0.9)394Human
RSV clinical strain 718Plaque assay, HEp-2 cells0.51 (0.4–0.7)533Human
  • a The potency of NHC against different IAVs, IBVs, and RSVs was determined in cultured cells or embryonated chicken eggs. IAVs are sorted by lineage and subtype. EC50s were determined through four-parameter variable-slope regression modeling, with 95% confidence intervals in parentheses. NA, not applicable.