Table 6 Identification of amino acid substitutions in H3 antigenic sites of H3N2 viruses. Antigenic sites of H3 protein were compared to vaccine strains Brisbane/2007. Here, we are presenting changes in antigenic sites of viruses isolated following any modification in H3N2 vaccine strain (2012, 2014, 2015, 2016 and 2017). Dash (−) indicates amino acid similar to vaccine sequence while amino acids different than vaccine strain are indicated in italics. Bold amino acids denote amino acid changes found in vaccine strains recommended for subsequent season in comparison to Brisbane/2007. Similarity of antigenic sites between vaccine strain and circulating viruses is shown as percentages in the last column
H3 | Similarity to vaccine strains (%) | |||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A1 | A2 | A3 | B1 | B2 | C1 | C2 | E1 | D | ||||||||||||||||||||||||
121 | 135 | 142 | 144 | 145 | 157 | 158 | 159 | 160 | 189 | 194 | 53 | 278 | 62 | 212 | 215 | |||||||||||||||||
Brisbane/2007 | N | T | R | N | N | L | K | F | K | N | L | D | N | E | T | P | A | B | C | E | D | |||||||||||
2009 | – | – | – | – | – | – | K | N | – | – | K | – | – | – | – | – | A | – | 100 | 89.5 | 100 | 100 | 97 | |||||||||
Perth/2009 | N | T | R | K | N | L | N | F | K | K | L | D | N | K | T | S | ||||||||||||||||
2012 | – | – | – | K | N | N | S | – | – | – | – | – | – | D | A | P | – | A | P | 90 | 100 | 84 | 100 | 88 | ||||||||
Victoria/2011 | N | T | R | N | N | L | N | F | K | K | L | D | N | E | A | P | ||||||||||||||||
2014 | – | – | G | – | S | L | S | – | F | Y | S | – | – | – | – | – | – | – | – | 90 | 89.5 | 84 | 100 | 100 | ||||||||
Texas/2012 | N | T | R | N | N | L | N | F | K | K | L | D | K | E | A | P | ||||||||||||||||
2015 | – | – | R | G | S | S | – | – | Y | T | – | – | – | – | – | – | – | 86.3 | 89.5 | 100 | 100 | 100 | ||||||||||
Switzerland/2013 | N | T | G | N | S | L | N | S | K | K | L | D | K | E | A | P | ||||||||||||||||
2016 | N | K | – | G | R | S | K | – | – | – | F | Y | – | – | – | – | N | K | N | – | – | – | 82 | 89.5 | 66.6 | 100 | 100 | |||||
Hong Kong/2014 | N | T | R | S | S | L | N | Y | K | K | P | D | K | E | A | P | ||||||||||||||||
2017 | K | K | R | G | S | K | – | – | – | – | T | – | L | – | – | – | – | – | 77 | 89.5 | 100 | 100 | 100 | |||||||||