In Vivo and In Vitro Alterations in Influenza A/H3N2 Virus M2 and Hemagglutinin Genes: Effect of Passage in MDCK-SIAT1 Cells and Conventional MDCK Cells

No mutations were detected in the hemagglutinin gene of influenza A/H3N2 virus isolates from patients undergoing short-term amantadine treatment. However, genetic changes occurred after serial passage in either MDCK or MDCK-SIAT1 cells. Our results showed that only a few mutations were observed in MDCK-SIAT1-passaged isolates in the presence of amantadine.