About the Authors
Department of Molecular Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
Department of Medical Sciences, Section for Infectious Diseases, Uppsala University Hospital, Uppsala, Sweden
The authors have declared that no competing interests exist.
Conceived and designed the experiments: SGEA. Performed the experiments: ECB OVP FG ASE KN. Analyzed the data: ECB ACF AC SGEA. Contributed reagents/materials/analysis tools: MH HL. Wrote the paper: ECB ACF SGEA.