ACKNOWLEDGEMENTS This work was supported by the following NIH grant R35HL139930 (JK), U54CA260581(JKK) and R21OD024931(XQ) as well as a grant form Emergent Ventures and the Paul Bechtner Foundation (JK) . This work was also partly supported by CRIP (Center for Research for Influenza Pathogenesis), a NIAID supported Center of Excellence for Influenza Research and Surveillance (CEIRS, contract #HHSN272201400008C) and CRIPT (Center for Research on Influenza Pathogenesis and Transmission), a NIAID funded Center of Excellence for Influenza Research and Response (CEIRR, contract #75N93021C00014), by DARPA grant HR0011-19-2-0020, and by the generous support of the JPB Foundation, the Open Philanthropy Project (research grant 2020-215611 (5384)), and anonymous donors to AG-S. The following reagent was produced under HHSN272201400008C and obtained through BEI Resources, NIAID, NIH: Spike Glycoprotein Receptor Binding Domain (RBD) from SARS-Related Coronavirus 2, Wuhan-Hu-1, Recombinant from HEK293 Cells, NR-52306. The S-Tag of SARS, S-Tag of SARS2 containing plasmids were kindly provided by Dr. Thomas Gallagher (Loyola University Chicago). We are grateful for technical help from Cecily C Midkiff in the histological core of Tulane National Primate Research Center and Christopher J Monjure and Tammy Bavaret in the Tulane ABSL3 core. We appreciate Dr. Florian Krammer (Professor of Vaccinology, Icahn School of Medicine at Mount Sinai in New York) for providing us the spike proteins including variants of concern. We thank Randy Albrecht for support with the BSL3 facility and procedures at the ISMMS.

These are raw data for figures in ACE2-IgG1 fusions with improved in vitro and in vivo activity against SARS-CoV-2, in iScience: PMID: 34957381