In August 2024 Tonix Pharmaceuticals “reiterated its commitment” to advancing the development of its live attenuated virus vaccine TNX-801 for the prevention of mpox and other infectious diseases. This comes after WHO declared that the spread of mpox in Africa represents a public health emergency of international concern. TNX-801 is a live replicating attenuated vaccine candidate, based on horsepox, and is believed to provide protection with “better tolerability” than 20th century vaccinia viruses.
TNX-801
The platform behind TNX-801 was chosen by US NIH for Project NextGen efforts against SARS-CoV-2 but has also protected animals against lethal challenge with intratracheal Clade 1 monkeypox virus. Tonix states that the recombinant horsepox virus vaccine uses a live replicating, attenuated virus that has “been shown to be >1,000-fold more attenuated than 20th century vaccinia” (VACV) strains in immunocompromised mice. The virus can be engineered to express foreign genes and is a strong platform for vaccine development because they have:
- Large packaging capacity for exogenous DNA inserts
- Precise virus-specific control of exogenous gene insert expression
- Lack of persistence or genomic integration in the host
- Strong immunogenicity as a vaccine
- The ability to rapidly generate vector/insert constructs
- Potential to be readily manufacturable at scale
- The ability to provide direct antigen presentation
Although Tonix’s current formulation is a frozen liquid, the team indicates that future lyophilised versions could be stored and shipped at standard refrigeration.
“Horsepox-based vaccines are designed to be single dose, vial-sparing vaccines that can be administered without sterile injection, manufactured using conventional cell culture systems with the potential for mass scale production, and packaged in multi-dose vials.”
A need for accelerated efforts
Dr Seth Lederman, Chief Executive Officer of Tonix, recognises that the WHO declaration “underscores the urgent need for additional treatments to stop these outbreaks and save lives”.
“We are motivated to advance development for our mpox vaccine with urgency given the global public health emergency.”
Dr Lederman states that TNX-801 “combines immune protection with improved tolerability and safety” and has the advantage of a single dose administration.
“Also, the stability of live virus vaccines eliminates the need for ultra-cold storage which complicates the widespread use of mRNA vaccines in Africa, where they are needed most right now.”
We look forward to hearing more about Tonix’s mpox vaccine development at the Congress in Barcelona this October. To join us get your tickets here, and don’t forget to subscribe to our weekly newsletters for vaccine updates.
