CD209 and infection: In contrast, insertion of three glycosylation sites in HA of A/Netherlands/602/09 (A/Netherlands/602/09-VN54 N125 N160), increased infection percentages of DC-SIGN expressing cells considerably compared to wild type virus and this virus infected DC-SIGN expressing cells almost as good as untreated cells with sialic acids on their surface (96%+/−1% and 70.6%+/−3% for MDCK DC-SIGN and Vero DC-SIGN, respectively).