Comparison of amino acid positions related to antigenic variation of H1N1 seasonal influenza viruses identified by current and previous studies.

aTwenty-three antigenicity-associated sites identified by random forest regression.bTwenty antigenicity-associated sites identified by support vector regression based on recursive feature elimination.cForty-one natural epitope residues identified by Huang et al. [13].dFifteen cluster-difference substitutions revealed by antigenic cartography.eFive antigenic epitope regions described by Brownlee and Fodor [37].Comparison of amino acid positions related to antigenic variation of H1N1 seasonal influenza viruses identified by current and previous studies.