Core Viewpoint - The effectiveness of antiviral drug Oseltamivir against A(H3N2) influenza remains intact despite rising flu cases in China, with a significant proportion of reported cases linked to this strain [1][5]. Group 1: Flu Activity and Statistics - As of the end of November 2025, China reported a total of 4,351 influenza-like illness outbreaks, with 3,313 cases (approximately 76.14%) associated with A(H3N2) [1][3]. - The ILI percentage in southern provinces reached 10.3% in the 48th week of 2025, an increase from 7.8% the previous week and higher than the same period in 2022, 2023, and 2024 [3]. - Northern provinces reported an ILI percentage of 9.1% in the same week, up from 8.6% the previous week, also exceeding the levels of the previous three years [3]. Group 2: Antiviral Drug Resistance - The National Influenza Center's analysis indicated that 3.9% of A(H1N1)pdm09 strains showed reduced sensitivity to neuraminidase inhibitors, while all A(H3N2) and B strains remained sensitive [5]. - Oseltamivir is still widely used and effective against A(H3N2), with clinical observations suggesting that resistance issues are not significant at this time [5][6]. Group 3: Antiviral Drug Guidelines - The "Chinese Influenza Treatment and Drug Prevention Clinical Practice Guidelines (2025 Edition)" states that antiviral drugs should be considered a supplementary measure to vaccination for flu prevention in community settings [6][7]. - Routine use of antiviral drugs for pre-exposure prevention is not recommended due to potential for inducing resistance and associated costs, with specific exceptions for high-risk groups [7].