On Mar. 17, 2021, Tonix Pharma 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 spike protein.

Immunogenicity and protective efficacy of single-dose TNX-1800 were assessed at two dose levels. Protection was assessed at Day 47, six days after challenge. The research was part of an ongoing collaboration between Southern Research, the University of Alberta and Tonix.