Phase I

Phase II

Phase III

Smallpox and Monkeypox Preventing Vaccine


TNX-801 is a novel, live virus vaccine based on synthesized horsepox (sHPXV). It is being developed as a potential smallpox preventing vaccine for widespread immunization and national stockpile. Though it shares structural characteristics with vaccinia-based vaccines, TNX-801 has unique properties that Tonix believes it may lower toxicity and offer potential safety advantages over existing vaccinia-based vaccines, which have been associated with adverse side effects such as myocarditis/pericarditis2.

Molecular analysis suggests that TNX-801 is closer than modern vaccines in DNA sequence1,2 to the vaccine discovered and disseminated by Dr. Edward Jenner. Molecular analysis indicates that HPXV has “complete” left and right inverted terminal repeats (ITRs) while different VACV isolates have a variety of deletions in the left and right ITRs. Therefore, TNX-801 has additional genes, relative to VACV vaccines, that may play roles in host immune interactions and one or more or such proteins may serve as antigens for protective immunity. TNX-801 has been assembled using synthetic DNA fragments1.


1Noyce RS, Lederman S, Evans DH. Construction of an infectious horsepox virus vaccine from chemically synthesized DNA fragments. PLoS One. 2018;13(1):e0188453.
2Engler RJ, Nelson MR, Collins LC, Jr., Spooner C, Hemann BA, Gibbs BT, Atwood JE, Howard RS, Chang AS, Cruser DL, Gates DG, Vernalis MN, Lengkeek MS, McClenathan BM, Jaffe AS, Cooper LT, Black S, Carlson C, Wilson C, Davis RL. A prospective study of the incidence of myocarditis/pericarditis and new onset cardiac symptoms following smallpox and influenza vaccination. PLoS One. 2015;10(3):e0118283.
TNX-801 is an investigational new biologic and has not been approved for any indication.