Tonix Pharmaceuticals Presented Data on Potential Mpox Vaccine TNX-801 at World Vaccine Congress Washington 2025
April 24, 2025
Tonix Pharmaceuticals has unveiled promising preclinical data for TNX-801, a novel single-dose live-virus mpox vaccine, at the 2025 World Vaccine Congress. TNX-801, based on synthesized horsepox, showed strong protection against both rabbitpox and clade IIa mpox in animals—including immunocompromised models—after just one dose. The vaccine prevented clinical disease and lesion formation, supporting its potential as a safe, effective alternative to multi-dose vaccines. With mpox outbreaks involving clade IIb and clade Ib declared international emergencies by the World Health Organization, TNX-801’s alignment with WHO’s preferred vaccine profile strengthens its promise in bolstering global preparedness and rapid response to future epidemics.
At the 2025 World Vaccine Congress in Washington, D.C., Tonix Pharmaceuticals presented compelling preclinical data on its investigational vaccine TNX-801, a single-dose, attenuated live-virus candidate designed to combat mpox and smallpox. In animal studies, TNX-801 demonstrated durable protection against lethal mpox and rabbitpox challenges and was well tolerated even in immunocompromised models. The vaccine is based on synthesized horsepox and showed broad efficacy against various mpox clades, including clade Ia and clade IIa, effectively preventing both clinical illness and lesion development.
CEO Dr. Seth Lederman emphasized the importance of TNX-801 in the context of the ongoing clade IIb and clade Ib mpox epidemics, both declared Public Health Emergencies of International Concern (PHEICs) by the World Health Organization. The vaccine’s single-dose regimen offers a critical advantage in outbreak settings where rapid, widespread immunization is essential. TNX-801's performance aligns with the WHO’s draft Target Product Profile (TPP) for mpox vaccines, which prioritizes single-dose durability, ease of administration, ambient-temperature stability, and suitability for use in immunocompromised populations.
As mpox continues to affect diverse regions and populations, including vulnerable groups, the need for next-generation vaccines is urgent. TNX-801’s promising efficacy and tolerability position it as a strong candidate for both endemic prevention and outbreak containment strategies. Tonix’s ongoing development reflects broader efforts to innovate beyond legacy smallpox vaccines and enhance global readiness for zoonotic poxvirus threats.
With additional clinical trials anticipated, TNX-801 may play a pivotal role in fortifying public health infrastructure against mpox resurgence and ensuring equitable access to protective immunization—particularly in settings where conventional multi-dose regimens are impractical. The next steps will be critical in translating preclinical promise into human-use authorization and scalable deployment.