About the Authors

Lisa C Lindesmith

Contributed equally to this work with: Lisa C Lindesmith, Eric F Donaldson

Affiliation University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America

Eric F Donaldson

Contributed equally to this work with: Lisa C Lindesmith, Eric F Donaldson

Affiliation University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America

Anna D LoBue

Affiliation University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America

Jennifer L Cannon

Affiliations University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America , Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America

Du-Ping Zheng

Affiliation Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America

Jan Vinje

Affiliation Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America

Ralph S Baric

To whom correspondence should be addressed. E-mail: ralph_baric@unc.edu

Affiliation University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, United States of America

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

RSB designed the study and contributed to the writing of the paper. LCL designed the study, collected and analyzed the data, and contributed to the writing of the paper. EFD, ADL, and DPZ collected data, performed experiments, analyzed the data, and contributed to the writing of the paper. JLC collected data, performed experiments, and contributed to the writing of the paper. JV contributed to the writing of the paper.