1. Crucell Vaccine Institute, Janssen Center of Excellence for Immunoprophylaxis, Archimedesweg 4-6, 2301 CA Leiden, Netherlands.
2. Crucell Vaccine Institute, Janssen Center of Excellence for Immunoprophylaxis, 3210 Merryfield Row, San Diego, CA 92121, USA.
3. Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.