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.

“We are pleased that all eight animals vaccinated with TNX-1800 had undetectable SARS-CoV-2 in their upper and lower airways 6 days after challenge with SARS-CoV-2,” said Seth Lederman, M.D., President and Chief Executive Officer of Tonix Pharmaceuticals. “Today’s results are from the second phase of a study in which TNX-1800 vaccinated and control animals were challenged with SARS-CoV-2.

Last Fall, we reported that all eight of animals vaccinated manifested ‘takes’, a skin reaction to horsepox vaccination which is a validated biomarker of functional T cell immunity, and that vaccination was associated with neutralizing antibodies in each case.

The positive results of the protection from live CoV-2 challenge that we are reporting today validate the capacity for TNX-1800 to protect against COVID-19, and also validate the ‘take’ after TNX-1800 vaccination as a biomarker for functional T cell immunity.”