High Levels of Non-Blocking Anti-Interferon and Anti-Cytokine Autoantibodies in Individuals with mRNA Vaccine-Induced Systemic Allergic ReactionsMuge Kalaycioglu MD1,2, Allan Feng1,2, Shaurya Dhingra1,2,3, Muhammad B. Khalid MD4, Kari C. Nadeau MD, PhD5, Paul J Utz MD1,2,6, Pamela A. Frischmeyer-Guerrerio MD, PhD4,61Department of Medicine, Division of Immunology and Rheumatology, Stanford University School of Medicine, Palo Alto, CA2 Institute for Immunity, Transplantation and Infection, Stanford University School of Medicine, Palo Alto, CA3College of Medicine, University of Illinois at Chicago, Chicago, IL4Food Allergy Research Section, Laboratory of Allergic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD5Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA6These authors contributed equallyCorresponding author: Muge Kalaycioglu, mugekal@stanford.edu, 6508890995Disclosure Statement: PJU was supported by the Henry Gustav Floren Trust, the Stanford Department of Medicine Team Science Program; funding from the Stanford Medicine Office of the Dean (to PJU); and National Institute of Allergy and Infectious Diseases/NIH 1 R01 AI182319-01. PA-FG and MBK were supported by the Division of Intramural Research (grant AI001336), National Institute of Allergy and Infectious Diseases, NIH.Disclosure of potential conflict of interest : The authors declare that they have no relevant conflicts of interest.