On Sept. 15, 2020,Tonix Pharmaceuticals announced that the first patient was enrolled in the observational COV-LOGIC study (TNX-C001), a study of humoral (antibody) and cellular (T cell) immune responses to SARS-CoV-2 in volunteers who have recovered or remain asymptomatic after exposure to COVID-19. The research was part of an ongoing and broader collaboration between Tonix and Southern Research to develop and conduct animal testing of Tonix’s TNX-1800, a live replicating, attenuated virus vaccine designed to protect against COVID-19.

The COV-LOGIC study is an observational multi-cohort sample collection study designed to collect the blood and nasopharyngeal (NP) swabs from individuals who have, and have not, been previously infected with SARS-CoV-2, or who have been intimately exposed to persons confirmed to have been infected with SARS-CoV-2, in order to analyze their antibody titers and T-cell responses to specific proteins of SARS-CoV-2 and to detect SARS-CoV-2 RNA which may be persistent in the nasopharynx at the time of sampling. For those individuals in whom viral RNA is detected during initial sampling, repeat blood and NP swab samples may be collected to examine temporal virus/immune response dynamics. In addition, blood will be collected for DNA extraction and exome sequencing in order to assess whether host genetic factors might influence these humoral or cellular responses or viral persistence (if identified).

TNX-1800 is a live modified horsepox virus vaccine for percutaneous administration that is designed to express the Spike protein of the SARS-CoV-2 virus that causes COVID-19 and to elicit a predominant T cell response.  Horsepox and vaccinia are closely related orthopoxviruses that are believed to share a common ancestor.  Live replicating orthopoxviruses, like vaccinia or horsepox, can be engineered to express foreign genes and have been explored as platforms for vaccine development because they possess; (1) large packaging capacity for exogenous DNA inserts, (2) precise virus-specific control of exogenous gene insert expression, (3) lack of persistence or genomic integration in the host, (4) strong immunogenicity as a vaccine, (5) ability to rapidly generate vector/insert constructs, (6) readily manufacturable at scale, and (7) ability to provide direct antigen presentation. Relative to vaccinia, horsepox has substantially decreased virulence in mice.  Horsepox-based vaccines are designed to be single dose, vial-sparing vaccines, which can be manufactured on conventional cell culturing systems, with the potential for mass scale production.