About the Authors

Katarina Widgren

widgren.katarina@gmail.com

Affiliations Department of Epidemiology, Statens Serum Institut, Copenhagen, Denmark, European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden

Jens Nielsen

Affiliation Department of Epidemiology, Statens Serum Institut, Copenhagen, Denmark

Kåre Mølbak

Affiliation Department of Epidemiology, Statens Serum Institut, Copenhagen, Denmark

Competing Interests

The authors have declared that no competing interests exist.

Author Contributions

Conceived and designed the experiments: KW KM. Performed the experiments: KW. Analyzed the data: KW JN. Contributed reagents/materials/analysis tools: JN. Wrote the paper: KW KM.