Cross-sectional study on protective antibodies against influenza A virus subtypes and cross-protection against influenza A(H3N2) subclade K, Portugal, August 2025. - Guiomar R; Henriques C; Pereira da Silva S; Gomes L; Dias D; Verdasca N; Nunes B; Rodrigues AP (Euro surveillance : bulletin Europeen sur les maladies transmissibles = European communicable disease bulletin, 2026)