Structural basis of antigenic drift in FMDV O/Cathay topotype variants revealed by porcine-derived single B-cell neutralizing antibodies.

Structural analysis reveals mutations at residues 73 and 134 on VP3 mediate neutralization escape in O/Cathay FMDV variants, explaining antigenic drift.

• Why it matters: Understanding the structural basis of antigenic drift in FMDV is crucial for improving vaccine efficacy against emerging variants that evade immune responses.
• What they did: Seven porcine-derived neutralizing monoclonal antibodies were used to map antigenic regions, and cryo-EM structures of virus variants were analyzed to identify key mutations.
• The result: Mutations at VP3 residues 73 and 134 disrupt hydrophobic interactions, hydrogen bonds, and salt bridges, providing a molecular framework for designing broad-spectrum vaccines.