Richard Aspinall1
, Giuseppe Del Giudice2
, Rita B Effros3
, Beatrix Grubeck-Loebenstein4
and Suryaprakash Sambhara5 
1Department of Immunology, Imperial College, London, UK
2Novartis Vaccines, Via Fiorentina 1, 53100 Siena, Italy
3Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, USA
4Institute for Biomedical Aging Research, Austrian Academy of Sciences, Innsbruck, Austria
5Influenza Division, Centers for Disease Control and Prevention, Atlanta, USA