F.M. Moesker, J.J.A. van Kampen, G. Aron, M. Schutten, D.A.M.C. van de Vijver,M.P.G. Koopmans, A.D.M.E. Osterhaus, P.L.A. Fraaij,Department of Viroscience, Erasmus MC, Rotterdam, The Netherlands Department of Paediatrics, Erasmus MC—Sophia, Rotterdam, The Netherlands Viroclinic Biosciences BV, Rotterdam, The Netherlands Research Center for Emerging Infections and Zoonoses (RIZ), University of Veterinary Medicine, Hannover, Germany