Table 2. Numbers of putative class I epitopes discovered in four emerging avian H7N9 strains and numbers of those epitopes conserved (at least 80% amino acid similarity) in recently circulating and vaccine backbone influenza strains.
| H7N9 Ag | Putative epitopes | Published | Other H7N9 | 2012/2013 vaccine strains | 2013/2014 vaccine recommendations | Vaccine backbone | |||
|---|---|---|---|---|---|---|---|---|---|
| A/California/ 7/2009 (H1N1) | A/Victoria/ 361/2011 (H3N2) | A/Christchurch/ 16/2010 (H1N1) | A/Texas/ 50/2012 (H3N2) | TIV | LAIV | ||||
| A/Puerto Rico/ 8/34 (H1N1) |
A/Ann Arbor/7/67 (H2N2) | ||||||||
| HA | 150 | 0 | 122 | 2 | 2 | 2 | 2 | ||
| M1 | 89 | 17 | 52 | 55 | 45 | 55 | 45 | 53 | 45 |
| M2 | 53 | 0 | 38 | 26 | 22 | 26 | 22 | 21 | 19 |
| NA | 146 | 0 | 130 | 1 | 1 | 1 | 1 | ||
| NEP | 53 | 1 | 45 | 12 | 20 | – | 20 | 26 | 30 |
| NP | 146 | 8 | 126 | 59* | 59 | – | 60 | 77 | 67 |
| NS1 | 91 | 1 | 32 | 18 | 15 | – | 15 | 27 | 21 |
| PA | 150 | 6 | 130 | 115 | 103 | – | 104 | 118 | 109 |
| PB1 | 150 | 15 | 137 | 111 | 115 | – | 115 | 111 | 123 |
| PB1-F2 | 64 | 0 | 15 | – | 0 | – | 0 | 3 | 4 |
| PB2 | 150 | 0 | 140 | 123 | 90 | – | 90 | 103 | 110 |
Counts of published epitopes from IEDB mapped to H7N9 epitopes discovered here are shown in the third column. Table values marked with ‘–‘ represent an antigen (Ag) that was unavailable for download. Epitope sequences from HA and NA are less conserved among other strains than epitopes derived from the internal proteins. *A/California/7/2009 NP sequence accessed from GISAID was truncated and did not cover C-terminal NP ICS.