About the Authors

Orlando Mayorga Perez

Affiliation Department of Microbiology and Parasitology, Faculty of Medical Sciences, National Autonomous University, León, Nicaragua

Martin W. G. Brinkhof

Current address: Swiss Paraplegic Research, Nottwil, Switzerland

Affiliation Institute of Social & Preventive Medicine (ISPM), University of Berne, Berne, Switzerland

Matthias Egger

Affiliation Institute of Social & Preventive Medicine (ISPM), University of Berne, Berne, Switzerland

Gert Frösner

Affiliation Max von Pettenkofer Institute, Ludwig-Maximilians University, Munich, Germany

Christian Herzog

Current address: Institute of Social & Preventive Medicine, University of Bern, Bern, Switzerland

Affiliation Crucell Switzerland AG, Berne, Switzerland

Marcel Zwahlen

zwahlen@ispm.unibe.ch

Affiliation Institute of Social & Preventive Medicine (ISPM), University of Berne, Berne, Switzerland

Competing Interests

OMP received in the past research funding from Crucell for vaccine studies, GF was in the past and at the time of the study providing laboratory support for Crucell's hepatitis A vaccine projects and CH was at the time of the study an employee of Crucell. There are no other disclosures of possible conflicts of interest. There are no patents, products in development or marketed products to declare. The disclosed potential competing interests do not alter the authors' adherence to all the Plos ONE policies on sharing data and materials.

Author Contributions

Conceived and designed the experiments: OMP CH ME. Performed the experiments: OMP GF. Analyzed the data: MWGB MZ. Wrote the paper: CH. Contributed to interpretation of the data: CH GF ME MWGB MZ. Contributed to the drafting of the manuscript: MWGB MZ. Contributed to the writing of the paper: ME MWGB MZ. Executed laboratory tests: GF.