$Tonix医药控股(TNXP)$ Multiple COVID-19 Vaccines in Development
In February 2020, Tonix announced a research collaboration with Southern Research to develop a vaccine (TNX-1800) against the novel coronavirus, SARS-CoV-2, and in May 2020 a collaboration with the University of Alberta was announced for three new vaccines (TNX-1810, TNX-1820, TNX-1830) targeting SARS-CoV-2. Each of the vaccines are based on the company’s horsepox vector platform. TNX-1800 is designed to elicit a predominantly T cell response to the SARS-CoV-2 spike protein. TNX-1810, TNX-1820, and TNX-1830 are designed to elicit an almost purely T cell response and express different SARS-CoV-2 antigens than the spike protein. On June 1, 2020, Tonix announced an agreement whereby FUJIFILM Diosynth Biotechnologies will manufacture the clinical trial supply of TNX-1800.
A recent publication examined the T cell response in patients who have recovered following infection with SARS-CoV-2 (Grifoni et al., 2020). CD8+ and CD4+ T cells responsive to SARS-CoV-2 peptide epitopes were identified in approximately 70% and 100% of patients, respectively. The CD4+ T cell responses to spike protein were robust, with the M and N proteins being other major targets. Less common responses were seen to nsp3, nsp4, ORF3a, and ORF3. For CD8+ T cells, spike and M protein were major targets along with at least eight other viral proteins. Surprisingly, CD4+ T cells that reacted to SARS-CoV-2 were found in approximately 40-60% of unexposed individuals, which could represent cross-reactivity between T cells that react to ‘common cold’ coronaviruses and SARS-CoV-2. These results point to the importance of a T cell response in combating SARS-CoV-2 and why vaccines to prevent COVID-19 should focus on generating a robust T cell response.
Tonix is one of the few companies developing a SARS-CoV-2 vaccine utilizing a live, replicating viral vector that is designed to generate a predominant T cell response and the only company utilizing the horsepox vector. Orthopoxviruses are known to induce strong innate