As shown in Table 2, the NA H275Y mutant viruses exhibited IC50 values 1,160- to 1,340-fold higher for oseltamivir, 203- to 254-fold higher for peramivir, 1.2- to 1.3-fold higher for zanamivir, 1.6- to 1.7-fold higher for laninamivir, and 0.9- to 1.2-fold higher for baloxavir, respectively, compared with the median IC50 values of wild-type A(H1N1)pdm09 viruses isolated in the 2024/25 influenza season in Japan. Here, XK is linked to influenza.