Antigenic Characterization of H1N1 Influenza Viruses That Circulated During the 2019-2020 Season in Philadelphia, Pennsylvania. - Mendoza LM; Anderson EM; Leonard AS; McFarland AG; Ort JT; Tanenbaum N; Durosinmi A; Bushman FD; Glaser LJ; Nachamkin I; Hensley SE (Influenza and other respiratory viruses, 2025)