1 Comparison of infectious SARS-CoV-2 from the nasopharynx of vaccinated and unvaccinated individuals Mario A. Peña-Hernández 1,2, *, Jon Klein 1,3 *, Amyn A. Malik 4,5, *, Andreas Coppi 4,6, *, Chaney Kalinich 7, *, Chantal B. F. Vogels 7 , Julio Silva 1,3 , Yale SARS-CoV-2 Genomic Surveillance Initiative 7 , David R. Peaper 8 , Marie-Louise Landry 8,9,10 , Craig Wilen 1,8 , Nathan D. Grubaugh 7 , Wade Schulz 6,8 , Saad B. Omer 5,7,9,11 , Akiko Iwasaki 1,7,12,13,‡ 1 Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA 2 Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT, USA 3 MD/PhD Program, Yale School of Medicine, New Haven, CT, USA 4 Department of Internal Medicine, Yale School of Medicine, New Haven, CT, USA. 5 Yale Institute for Global Health, Yale School of Public Health, New Haven, CT, USA 6 Center for Outcomes Research and Evaluation, Yale New Haven Hospital, New Haven, CT, USA 7 Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA 8 Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, USA 9 Section of Infectious Diseases, Department of Medicine, Yale School of Medicine, New Haven, CT, USA 10 Clinical Virology Laboratory, Yale New Haven Health, New Haven, CT, USA 11 Yale School of Nursing, Yale University, New Haven, CT, USA 12 Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, US 13 Howard Hughes Medical Institute, Chevy Chase, MD, USA * Indicates equal contributions ‡ Corresponding Author . CC-BY-NC-ND 4.0 International license It is made available under a perpetuity. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint The copyright holder for this this version posted January 8, 2022. ; https://doi.org/10.1101/2021.12.28.21268460 doi: medRxiv preprint NOTE: This preprint reports new research that has not been certified by peer review and should not be used to guide clinical practice.