Table 1.
Amino acid similarity (%) between vaccine antigens and challenge strains
| Vaccine antigen | |||||
|---|---|---|---|---|---|
| Viruses | B/Phu HA | B/Col HA | B/Col NA | B/Col NP | B/Col M2 |
| B/Lee/1940 | 91.27 | 91.94 | 88.84 | 95.71 | 81.65 |
| B/Malaysia/2506/2004 (V) | 92.98 | 97.94 | 96.35 | 98.21 | 97.25 |
| B/Colorado/06/2017 (V) | 92.28 | 100 | 100 | 100 | 100 |
| B/New York City/PV01181/2018 (V) | 92.62 | 99.66 | 99.14 | 99.82 | 100 |
| B/Florida/04/2006 (Y) | 98.29 | 92.62 | 94.85 | ||
| B/Phuket/3073/2013 (Y) | 100 | 92.28 | 93.78 | 99.20 | 91.74 |
| B/New York City/PV00094/2017 (Y) | 99.66 | 92.28 | 93.13 | 99.29 | 89.91 |
Amino acid sequences from vaccine antigens (B/Phu HA, B/Col HA, B/Col NA, B/Col NP or B/Col M2) were aligned to amino acid sequences of proteins from influenza virus strains used in this study (B/Lee/1940, B/Malaysia/2506/2004 (V), B/Colorado/06/2017 (V), B/New York City/PV01181/2018 (V), B/Florida/04/06 (Y), B/Phuket/3073/2013 (Y) or B/New York City/PV00094/2017 (Y) using the Clustal Omega multiple sequence alignment tool. Amino acid sequences of NP and M2 from B/Florida/04/2006 (Y) were not assessed. The percent (%) amino acid identity was determined using the computed percent identity matrix and examined for each challenge virus.