1. Novartis Institutes for BioMedical Research, Cambridge, MA 02139, USA.
2. Novartis Vaccines and Diagnostics, 53100 Siena, Italy.
3. Novartis Vaccines and Diagnostics, Cambridge, MA 02139, USA.
4. Novartis Pharmaceuticals Corporation, East Hanover, NJ 07936, USA.
5. Novartis Pharmaceuticals Corporation, CH-4002 Basel, Switzerland.
6. Stanford University School of Medicine, Stanford, CA 94305–5124, USA.
7. Southern Clinical Trials, Christchurch 8024, New Zealand.