• FluTrackers.com Inc. does not provide medical advice. Information on this web site is collected from various internet resources, and the FluTrackers board of directors makes no warranty to the safety, efficacy, correctness or completeness of the information posted on this site by any author or poster. The information collated here is for instructional and/or discussion purposes only and is NOT intended to diagnose or treat any disease, illness, or other medical condition. Every individual reader or poster should seek advice from their personal physician/healthcare practitioner before considering or using any interventions that are discussed on this website. By continuing to access this website you agree to consult your personal physican before using any interventions posted on this website, and you agree to hold harmless FluTrackers.com Inc., the board of directors, the members, and all authors and posters for any effects from use of any medication, supplement, vitamin or other substance, device, intervention, etc. mentioned in posts on this website, or other internet venues referenced in posts on this website.
  • We are not asking for any donations. Do not donate to any entity who says they are raising funds for us.

mBio . Characterization of A/H7 influenza virus global antigenic diversity and key determinants in the hemagglutinin globular head mediating A/H7N9

tetano

Editor, Senior Moderator
mBio


. 2023 Aug 11;e0048823.
doi: 10.1128/mbio.00488-23. Online ahead of print. Characterization of A/H7 influenza virus global antigenic diversity and key determinants in the hemagglutinin globular head mediating A/H7N9 antigenic evolution

Adinda Kok[SUP] 1 [/SUP], Rachel Scheuer[SUP] 1 [/SUP], Theo M Bestebroer[SUP] 1 [/SUP], David F Burke[SUP] 2 [/SUP], Samuel H Wilks[SUP] 2 [/SUP], Monique I Spronken[SUP] 1 [/SUP], Dennis de Meulder[SUP] 1 [/SUP], Pascal Lexmond[SUP] 1 [/SUP], Mark Pronk[SUP] 1 [/SUP], Derek J Smith[SUP] 2 [/SUP], Sander Herfst[SUP] 1 [/SUP], Ron A M Fouchier[SUP] 1 [/SUP], Mathilde Richard[SUP] 1 [/SUP]



Affiliations
Abstract

Avian A/H7 influenza viruses are a global threat to animal and human health. These viruses continue to cause outbreaks in poultry and have caused the highest number of reported zoonotic infections to date, highlighting their pandemic threat. Evidence for antigenic diversification of avian A/H7 influenza viruses exists; however, knowledge of the drivers and molecular basis of antigenic evolution of these viruses is limited. Here, antigenic cartography was used to analyze the global antigenic diversity of A/H7 influenza viruses and to determine the molecular basis of antigenic change in A/H7N9 viruses. A phylogenetic tree based on all available A/H7 HA sequences was generated, from which 52 representative, genetically diverse, antigens were selected for antigenic characterization using hemagglutination inhibition assays. The resulting data were used to compute an antigenic map using multidimensional scaling algorithms. High antigenic relatedness was observed between antigens and sera belonging to genetically divergent A/H7 (sub)lineages. The most striking antigenic change relative to the timespan of virus isolation was observed for the A/H7N9 viruses isolated between 2013 and 2019 in China. Amino acid changes at positions 116, 118, 125, 130, 151, and 217 in the hemagglutinin globular head were found to be the main determinants of antigenic evolution between A/H7N9 influenza virus prototypes. The A/H7 antigenic map and knowledge of the molecular determinants of their antigenic evolution will aid pandemic preparedness against A/H7 influenza viruses, specifically regarding the design of novel vaccines and vaccination strategies. IMPORTANCE A/H7 avian influenza viruses cause outbreaks in poultry globally, resulting in outbreaks with significant socio-economical impact and zoonotic risks. Occasionally, poultry vaccination programs have been implemented to reduce the burden of these viruses, which might result in an increased immune pressure accelerating antigenic evolution. In fact, evidence for antigenic diversification of A/H7 influenza viruses exists, posing challenges to pandemic preparedness and the design of vaccination strategies efficacious against drifted variants. Here, we performed a comprehensive analysis of the global antigenic diversity of A/H7 influenza viruses and identified the main substitutions in the hemagglutinin responsible for antigenic evolution in A/H7N9 viruses isolated between 2013 and 2019. The A/H7 antigenic map and knowledge of the molecular determinants of their antigenic evolution add value to A/H7 influenza virus surveillance programs, the design of vaccines and vaccination strategies, and pandemic preparedness.

Keywords: antigenic cartography; antigenic evolution; avian influenza virus; hemagglutinin.

 
Back
Top