The VSV genome encodes for five major proteins: matrix protein (M), nucleoprotein (N), large polymerase protein (L), phosphoprotein (P), and glycoprotein (G). Importantly, vaccination protects hamsters against SARS-CoV-2 challenge, as demonstrated by the abrogation of body weight loss,?and? alleviation of the extensive tissue damage and viral loads in lungs and nasal turbinates. Taken together, we suggest the recombinant VSV-?G-spike as a safe, efficacious and protective vaccine against SARS-CoV-2. Subject terms: Vaccines, SARS-CoV-2 Here, the authors generate a replication-competent VSV based vaccine expressing SARS-CoV-2 spike protein and show protection in the hamster model with one dose. Analysis of the antibody response in mice shows induction of neutralizing antibodies and suggests a desirable Th1-biased response to the vaccine. Introduction Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a member of the family, is the causative agent of Coronavirus Disease 2019 (COVID-19)1C3. The computer virus was first explained in late 2019 in Wuhan, China, and rapidly spread globally. Over 45 million cases worldwide were diagnosed, with over 1.1 million deaths (as of November 3, 2020, covid19.who.int). SARS-CoV-2 is usually a single-stranded positive sense RNA computer virus decorated ZM 336372 with the spike (S) surface glycoprotein. The S protein is usually a highly glycosylated type I membrane protein. The homotrimeric business of the S protein around the viral membrane forms the typical coronaviruses S structures4. The S protein binds with high affinity to the angiotensin-converting enzyme 2 (ACE2) receptor. This binding induces membrane fusion and access of the SARS-CoV-2 into host cells, thus providing as a target for neutralizing antibodies5,6. The SARS-CoV-2 S protein is composed of two unique subunits, namely S1 and S2. The surface unit S1 binds the receptor, whereas the transmembrane unit S2 facilitates viral fusion to cell membranes. The S protein is activated by a cleavage at the spike S1/S2 site by host cell proteases7. Moreover, it has been ZM 336372 recently shown that this SARS-CoV-2 has a newly created furin cleavage site at the S1/S2 boundary. This novel feature dramatically affects viral access into Vero E6 and BHK-21 cells6. Vesicular stomatitis computer virus (VSV), a member of the family, is ZM 336372 usually a nonsegmented single-stranded unfavorable sense RNA computer virus. VSV causes disease in animals, with a broad host range from insects to mammals. However, human VSV contamination cases are rare. The VSV genome encodes for ZM 336372 five major proteins: matrix protein (M), nucleoprotein (N), large polymerase protein (L), phosphoprotein (P), and glycoprotein (G). The L and P proteins, together with the N, form the transcriptionally active subunit of the computer virus. The G protein mediates both viral binding and host cell fusion with the endosomal membrane following endocytosis, and cell access8. The recombinant VSV (rVSV) platform was developed by John Rose and Michael Whitt9,10. rVSV was previously developed as a vaccine platform for several viral pathogens, including Ebola computer virus (EBOV), human immunodeficiency computer virus, and CrimeanCCongo hemorrhagic fever computer virus11,12. As a vaccine platform, rVSV harbors several advantages: (1) The computer virus can be very easily propagated and reach high titers, (2) it elicits strong cellular and humoral immunity in vivo, (3) removal of the VSV-G protein, the major virulence factor of the VSV, attenuates the computer virus and reduces its reactogenicity, (4) VSV is usually sensitive to IFN-/, and an intact innate Alas2 immune response likely restricts its replication13, and (5) most of the general populace is usually seronegative for VSV14. As the need for any vaccine for SARS-CoV-2 is usually urgent, more than 200 vaccines are being rapidly developed using a variety of technologies, including over 40 vaccines that are currently tested in clinical trials (as of November 3, 2020, https://www.who.int/publications/m/item/draft-landscape-of-covid-19-candidate-vaccines). Among them are RNA and DNA vaccines, viral vectored vaccines, recombinant proteins, live attenuated and inactivated vaccines15, as well as several replicating VSV-based vaccines. Currently, several of these vaccines are in advanced clinical trial phases. Here, we designed an rVSV-based.