erved Neutralizing Epitope on Group 2 Influenza A Viruses Damian C. Eldert,1* Robert H. E. Friesen,2 Gira Bhabha,1 Ted Kwaks,2 Mandy Ringeneelen,2 Wenli Ytt?' Carla Ophorst,2 Freek Cox,2 Hans J.W.M. Korse,2 Boerries Brandenburg,2 Ronald Vogels,2 Just P.J. Brakenhof1,2 Ronald Kompier,2f Martin H. Koldijk,