1. 1Institute for Disease Modeling, Global Health, Bill & Melinda Gates Foundation, Seattle, Washington;
2. 2Consultant to the Bill & Melinda Gates Foundation, Seattle, Washington;
3. 3Department of Computer Science, Vermont Complex Systems Center, University of Vermont, Burlington, Vermont;
4. 4Department of Computer Science, University of Vermont, Burlington, Vermont;
5. 5Network Science Institute, Northeastern University, Boston, Massachusetts;
6. 6Department of Marine and Environmental Sciences, Northeastern University, Boston, Massachusetts;
7. 7Department of Physics, Northeastern University, Boston, Massachusetts;
8. 8Department of Health Sciences, Northeastern University, Boston, Massachusetts;
9. 9ISI Foundation, Turin, Italy;
10. 10University of Washington, Seattle, Washington;
11. 11New Mexico State University, Las Cruces, New Mexico