Tonix Pharmaceuticals, Inc.. (Nasdaq: TNXP) (Tonix or the Company), a clinical-stage biopharmaceutical company, today announced preliminary results following vaccination of non-human primates with TNX-1800 (modified horsepox virus, live vaccine), a live attenuated COVID-19 vaccine candidate engineered to express the SARS-CoV-2 (CoV-2) spike protein. Immunogenicity and protective efficacy of single-dose TNX-1800 were assessed at two dose levels (n=4 per group). At Day 41 after the vaccination, animals were challenged with live SARS-CoV-2 through intra-nasal and intra-tracheal routes. Protection was assessed at Day 47, six days after challenge. The research is part of an ongoing collaboration between Southern Research, the University of Alberta and Tonix.