About the Authors
Seattle Biomedical Research Institute, Seattle, Washington, United States of America
Department of Global Health, University of Washington, Seattle, Washington, United States of America
The authors have declared that no competing interests exist.
Conceived and designed the experiments: MP. Performed the experiments: CW BCJ. Analyzed the data: CW BCJ MP. Wrote the paper: MP. Developed assays: CW. Reviewed the paper: CW. Designed the experiments: BCJ. Edited the paper: BCJ.