Contemporary H3N2 influenza viruses have a glycosylation site that alters binding of antibodies elicited by egg-adapted vaccine strains

H3N2 viruses continuously acquire mutations in the hemagglutinin (HA) glycoprotein that abrogate binding of human antibodies. During the 2014-2015 influenza season, clade 3C.2a H3N2 viruses possessing a new predicted glycosylation site in antigenic site B of HA emerged, and these viruses remain prevalent today. The 2016-2017 seasonal influenza vaccine was updated to include a clade 3C.2a H3N2 strain; however, the egg-adapted version of this viral strain lacks the new putative glycosylation site. Here, we biochemically demonstrate that the HA antigenic site B of circulating clade 3C.2a viruses is glycosylated. We show that antibodies elicited in ferrets and humans exposed to the egg-adapted 2016-2017 H3N2…

• BW
  Burroughs Wellcome Fund

  Award: 1015433
• NI
  National Institutes of Health

  Awards: HHSN272201400005C, 1R01AI108686, 1R01AI113047, DP2AI117921
• NI
  National Institute of Allergy and Infectious Diseases

  Awards: 1R01AI108686, HHSN272201400005C, DP2AI117921, CEIRS HHSN272201400005C, 1R01AI113047