1. Immunization Unit, Department of Infectious Disease Epidemiology, Robert Koch Institute , Berlin , Germany
2. Center for International Health Protection, Robert Koch Institute , Berlin , Germany
3. Mikrobiologisches Institut – Klinische Mikrobiologie, Immunologie und Hygiene, Friedrich Alexander Universität (FAU) Erlangen-Nürnberg and Universitätsklinikum Erlangen , Erlangen , Germany
4. Kleijnen Systematic Reviews Ltd , York , United Kingdom
5. Heidelberg Institute of Global Health, University of Heidelberg , Heidelberg , Germany
6. Institute of Social and Preventive Medicine, University of Bern , Bern , Switzerland