1. Institute for Research in Biomedicine, Università della Svizzera Italiana, CH-6500 Bellinzona, Switzerland.
2. Humabs BioMed SA, 6500 Bellinzona, Switzerland.
3. Vaccine Research Center, National Institute of Allergy and Infectious Diseases, Bethesda, MD 20892, USA.
4. U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA.
5. National Institute for Biomedical Research, National Laboratory of Public Health, Kinshasa B.P. 1197, Democratic Republic of the Congo.
6. Institute of Microbiology, ETH Zürich, CH-8093 Zürich, Switzerland.