Pre-existing neutralizing antibodies against cattle-transmitted influenza A virus H5N1 are detectable in unexposed individuals

The transmission of influenza A virus H5N1 clade 2.3.4.4b from cattle to humans highlights the risk of an H5N1 pandemic. Pre-existing immunity strongly impacts the course and severity of viral infections, making detailed knowledge of antibodies against the spilled-over strain crucial. Here, we assessed humoral immunity against H5N1 A/Texas/37/2024 in H5N1-naive individuals. We performed complementary binding and neutralization assays on 66 individuals and ranked activities among a panel of 76 influenza A virus isolates. We detected low but distinct cross-neutralizing titers against A/Texas/37/2024, with a 3.9- to 15.6-fold reduction compared with selected H1N1 or H3N2 strains. By cloning and characterizing 136…

• DZ
  Deutsches Zentrum für Infektionsforschung

  Award: FF02.901
• EC
  European Commission
• DF
  Deutsche Forschungsgemeinschaft

  Award: CRC1310
• BF
  Bundesministerium für Bildung und Forschung

  Award: 01KX2121
• HE
  HORIZON EUROPE Framework Programme
• HE
  HORIZON EUROPE European Innovation Council

  Award: 101084171
• EH
  European Health and Digital Executive Agency

  Award: 101202831