AUTHOR=Sablerolles Roos S. G. , Goorhuis Abraham , GeurtsvanKessel Corine H. , de Vries Rory D. , Huckriede Anke L. W. , Koopmans Marion P. G. , Lafeber Melvin , Postma Douwe F. , van Baarle Debbie , Visser Leo G. , Dalm Virgil A. S. H. , Kootstra Neeltje A. , Rietdijk Wim J. R. , van der Kuy P. Hugo M. TITLE=Heterologous Ad26.COV2.S Prime and mRNA-Based Boost COVID-19 Vaccination Regimens: The SWITCH Trial Protocol JOURNAL=Frontiers in Immunology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.753319 DOI=10.3389/fimmu.2021.753319 ISSN=1664-3224