1. Department of Biological Sciences, Faculty of Science, National University of Singapore, 117558 Singapore, Singapore
2. Programme in Emerging Infectious Diseases, Duke-NUS Medical School, 169857 Singapore, Singapore
3. Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117600 Singapore, Singapore
4. Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 119228 Singapore, Singapore
5. Saw Swee Hock School of Public Health, National University of Singapore, 117549 Singapore, Singapore