Vaccine Genome Researchers Report 99.7% Colinear Identity Between a U.S. Civil War Era Smallpox Vaccine and Horsepox Virus

Findings Published in the Current Issue of the Journal Genome Biology

Horsepox is the Vector for Tonix’s Experimental TNX-1800 COVID-19 Vaccine

Horsepox Has Been Used as a Smallpox Vaccine Since at Least the 1860’s

Smallpox is the Only Viral Disease Ever Eradicated

CHATHAM, N.J., Dec. 04, 2020 (GLOBE NEWSWIRE) -- Tonix Pharmaceuticals Holding Corp. (Nasdaq: TNXP) (Tonix or the Company), a clinical-stage biopharmaceutical company, announced today that independent researchers reported 99.7% colinear identity between a circa 1860 U.S. smallpox vaccine and horsepox virus. Tonix’s TNX-801 is a horsepox-based live virus vaccine being developed as a potential vaccine to prevent smallpox and monkeypox. Tonix’s TNX-801 is also the vector on which Tonix’s COVID-19 experimental vaccine is based. Tonix was not involved in the research reported.

The publication in the Journal Genome Biology, entitled “Re-assembly of 19th-century smallpox vaccine genomes reveals the contemporaneous use of horsepox and horsepox-related viruses in the United States”¹ analyzed sequences of U.S. smallpox vaccines that had been published recently by a different group also in Genome Biology, entitled “The origins and genomic diversity of American Civil War Era smallpox vaccine strains”².   The first paper applied modern techniques of sequencing old DNA to smallpox vaccine specimens stored in the Mütter Museum in Philadelphia, and identified that vaccines with horsepox core viral sequences were used in the 1860’s and referenced sequence information from several vaccines that the authors posted in GenBank, the National Institute of Health genetic sequence database. The new report re-assembled certain genomes from the GenBank sequences associated with the first paper and found a remarkable degree of identity with the circa 1860 U.S. smallpox vaccine VK05 and the 1976 Mongolian horspox isolate called MNR-76. Tonix’s TNX-801 was synthesized³ based on the sequence of the Mongolian horsepox isolate MNR-76⁴.

"The extent of colinear identity, approximately 99.7%, is remarkable between the circa 1860 U.S. smallpox vaccine VK05 and the 1976 Mongolian horsepox genome,” said, José Esparza, MD, PhD, Adjunct Professor at the Institute of Human Virology, School of Medicine of the University of Maryland, who was an author of the Genome Biology letter. “This finding indicates that a true horsepox virus was used as a smallpox vaccine in the U.S. in the 1860’s.  It is astonishing that there are so few differences between these viruses despite the separation of their isolation by over 100 years and from different continents.”