Table 1

Inhibition by PVP-I of sialidase activity, hemagglutination and infectivity activity of influenza A viruses

Virus subtype

Virus strain

Sialidase inhibition activity

IC50a (μg/ml)

Hemagglutination inhibition activityb (mg/ml)

Infection inhibitory activity (%)c


H1N1

A/Bel/42

11 ± 2

1.56

84 ± 1

A/Texas/36/91

72 ± 4

0.78

68 ± 3

A/USSR/92/77

47 ± 3

0.78

68 ± 2

A/PR/8/34

9.5 ± 0.5

0.20

62 ± 2

A/WS/33

12.5 ± 0.5

0.78

60 ± 4

A/WSN/33

45 ± 1

0.39

97 ± 1


A/DK/HK/36/4

21 ± 5

12.50

40 ± 4


H3N2

A/Aichi/2/68

96 ± 2

3.13

82 ± 5

A/Memphis/1/71

61 ± 4

1.56

66 ± 3


H9N2

A/DK/HK/92/76

212 ± 9

12.50

34 ± 8


H5N3

A/DK/HK/313/78

78 ± 4

12.50

23 ± 1

A/DK/HK/23/76

124 ± 7

3.13

57 ± 4

A/DK/HK/677/1

55 ± 1

3.13

50 ± 3


aIC50values are concentrations inhibiting viral sialidase activity by 50%. Standard error means were calculated from means of two independent experiments, each conducted in duplicate.

bMinimum concentration that inhibits hemagglutination.

cPercent viral inhibition (with 1.56 mg/ml of PVP-I) was calculated by comparison with the control without an inhibitor. Each experiment was performed in triplicate.

Sriwilaijaroen et al. Virology Journal 2009 6:124   doi:10.1186/1743-422X-6-124

Open Data