From the *Paediatric Infectious Diseases and Vaccinology Unit, University of Basel Children’s Hospital, Basel, Switzerland

†Faculty of Medicine, University of Basel, Basel, Switzerland.

Accepted for publication August 26, 2020.

U.H. is a member of the “Global Pertussis Initiative” (supported by Sanofi Pasteur, United States) and the “Collaboration of European Experts on Pertussis Awareness Generation,” CEEPAG (supported by Sanofi, France). The other authors have no conflicts of interest to disclose.

A list of “Swiss Paediatric Surveillance Unit” is given in “Acknowledgments” footnote.

Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s website (www.pidj.com)

Address for correspondence: Ulrich Heininger, MD, Paediatric Infectious Diseases and Vaccinology Unit, University of Basel Children’s Hospital, Spitalstrasse 33, CH-4056 Basel, Switzerland. E-mail: Ulrich.Heininger@ukbb.ch.