Skip to main content

Table 4 Amino-acid substitutions found in the HA protein of 550 influenza B viruses (145 Victoria and 405 Yamagata) analyzed in this study and detected in Italy during the period 2012–2017

From: Co-circulation of the two influenza B lineages during 13 consecutive influenza surveillance seasons in Italy, 2004–2017

SubunitResidue at site*Vic-1 (N = 145)Yam-2 (N = 169)Yam-3 (N = 236)
HA1120-loop (116–137)I117V (117)R118K (1)N116K (209)
V124A (1)S120 T (7)N116R (5)
N129D (127)T121S (10)Q122K (9)
 N123K (3)N123T (4)
 D126N (3)D126N (1)
150-loop (141–150)I146V (20)G141R (1)S148 N (1)
 T147A (1)S150I (1)I150V (1)
160-loop (162–167) N165Y (1)
D163N (1)
D163G (1)
190-helix (194–202)D197N (142)D196N (169)D196N (235)
 N197D (3)T198N (1)D196Y (1)
 T199A (2)N202S (2)K197R (4)
 T199I (1) S202 N (21)
 A202T (1)  
  1. *Amino acid substitutions reported in this table are compared with vaccine strains of respective clades and numbered according to respective vaccine strains (B/Brisbane/60/2008 for Vic-1, B/Massachusetts/02/2012 for Yam-2, B/Wisconsin/01/2010 for Yam-3). The number of influenza viruses carrying the substitution is indicated inside parenthesis