Table 3.: Genomic composition and rate of NA inheritance by reassortants of MDV and currently circulating influenza viruses of varying sensitivity to non-specific, heat-stable inhibitors in guinea pig serum.

WT Parental Strain1 Reassortants Generated2
Number of Viruses Tested Sensitivity to Inhibitors Total Number NA From Genomic Composition3
WT (%) MDV (%) 6:2 (%) 5:3 (%) 7:1 (%) Other (%)
Influenza A (H3N2) Viruses
5 Resistant 74 71 (95.9%) 3 (4.1%) 7 (9.5%) 25 (33.8%) 1 (1.4%) 41 (55.3%)
6 Sensitive 126 26 (20.6%) 100 (79.4%) 12 (9.5%) 13 (10.3%) 10 (7.9%) 91 (72.2%)
Influenza A (H1N1)4 Viruses
7 Resistant 136 130 (95.6%) 6 (4.4%) 71 (52.2%) 37 (27.2%) 0 28 (20.6%)
Influenza A (H2N2) Viruses
1 Resistant 5 5 (100%) 0 4 (80.0%) 1 (20.0%) 0 0
1 Sensitive 29 29 (100%) 0 0 4 (13.8%) 0 25 (86.2%)
Influenza A (H5N1) Viruses
2 Resistant 53 14 (26.4%) 39 (73.6%) 0 0 39 (73.6%) 14 (26.4%)
1 Sensitive 12 12 (100%) 0 0 0 0 12 (100%)
All Influenza A Viruses
14 Resistant 268 220 (82.1%) 48 (17.9%) 82 (30.6%) 63 (23.5%) 40 (14.9%) 83 (31.0%)
9 Sensitive 167 67 (40.1%) 100 (59.9%) 12 (7.2%) 17 (10.2%) 10 (6%) 128 (76.6%)
All Influenza B Viruses
6 Resistant 88 77 (87.5%) 11 (12.5%) 21 (23.9%) 30 (34.1%) 1 (1.1%) 36 (40.9%)
11 Sensitive 326 63 (19.3%) 263 (80.7%) 12 (3.7%) 12 (3.7%) 91 (27.9%) 211 (64.7%)

1The complete list of WT parental viruses is presented in Table 1. 2All reassortants inherited HA from WT parental viruses. 3Genomic composition: 6:2 are reassortants containing HA and NA from WT virus; 5:3 are reassortants containing HA and NA, from the WT parent, as well as WT NP, M, or NS gene; 7:1 are single gene reassortants containing only HA from WT virus. 4No inhibitor-sensitive WT viruses were found among the type A (H1N1) influenza viruses tested.