About the Authors
University of Würzburg, Institute of Hygiene and Microbiology, Würzburg, Germany
University of Würzburg, Institute of Virology and Immunobiology, Würzburg, Germany
The authors have declared that no competing interests exist.
Conceived and designed the experiments: JKN KP MBL KB. Performed the experiments: JKN KP. Analyzed the data: JKN KP MBL KB. Contributed reagents/materials/analysis tools: JKN KP MBL KB. Wrote the paper: JKN MBL KB.