Table 1.
Phenotypic characteristics of H3N2 LAIVs and Len/17 master donor virus.
| LAIV strain | Source of HA and NA (clade) | Source of NP | Distance to Len/17 NP, as substitutions | Virus titre in eggs, lgEID50/mL |
||
|---|---|---|---|---|---|---|
| 26 °C | 33 °C | 38 °C | ||||
| TX LAIV 6:2 | TX/12 (3c.1) | Len/17 | - | 7.0 ± 1.3 | 9.2 ± 0.5 | 2.2 ± 0.7 |
| TX LAIV 5:3 | TX/12 (3c.1) | TX/12 | 27 | 6.1 ± 0.5 | 8.1 ± 0.4 | 1.8 ± 0.3 |
| SW LAIV 6:2 | SW/13 (3c3.a) | Len/17 | - | 6.1 ± 0.4 | 8.1 ± 0.7 | 1.7 ± 0.4 |
| SW LAIV 5:3 | SW/13 (3c3.a) | SW/13 | 29 | 5.2 ± 0.7 | 7.8 ± 0.5 | 1.8 ± 0.3 |
| HK LAIV 6:2 | HK/14 (3c2.a) | Len/17 | - | 5.5 ± 0.5 | 7.9 ± 0.4 | 1.8 ± 0.5 |
| HK LAIV 5:3 | HK/14 (3c2.a) | HK/14 | 30 | 5.4 ± 0.7 | 7.5 ± 0.3 | 1.5 ± 0.3 |
| Len/17 | Len/17 | Len/17 | - | 6.9 ± 0.7 | 8.9 ± 0.3 | 1.9 ± 0.3 |
| TX/12 | TX/12 (3c.1) | TX/12 | 27 | 3.5 ± 0.8 | 9.0 ± 0.6 | 9.0 ± 0.5 |
| SW/13 | SW/13 (3c3.a) | SW/13 | 29 | 3.0 ± 0.8 | 7.0 ± 0.9 | 6.3 ± 1.0 |
| HK/14 | HK/14 (3c2.a) | HK/14 | 30 | 3.5 ± 0.9 | 8.4 ± 0.6 | 8.4 ± 1.1 |
TX/12: A/Texas/50/2012 (H3N2); NP accession number EPI408574; SW/13: A/Switzerland/9715293/2013 (H3N2); NP accession number EPI540519; HK/14: A/ Hong Kong/4801/2014 (H3N2); NP accession number EPI614430; Len/17: A/Leningrad/134/17/57 (H2N2); NP accession number EPI555083; Distances were calculated as number of amino-acid substitutions between wild-type and Len/17 NP sequences aligned by the multiple alignment tool of Geneious 6.0 software.