Our Proprietary VAAST™ Platform

Vaxart uses a specific virus called adenovirus type 5 (Ad5) as part of its novel VAAST™ platform to help train our immune system to recognize and defeat dangerous invading pathogens. Vaxart recombinantly removes the DNA Ad5 uses for viral replication, so the virus cannot make copies of itself.

Vaxart then uses the disabled Ad5 virus as a delivery system, or “vector,” to carry the genes coding for the “antigen,” a component of the target virus that is known to generate a protective immune response, and the “adjuvant,” a molecule that stimulates the innate immune system. The Ad5 vector delivers these two genes to the epithelial cells lining the mucosa of the small bowel.

When the altered Ad5 virus enters a cell and delivers the genes for the antigen and the adjuvant, the genes are expressed, and the cell manufactures the vaccine antigen for the immune system to recognize, as well as the adjuvant that stimulates the immune system to mount a targeted response against the vaccine antigen.

These two molecules “teach” the immune system to recognize the antigen, a specific component of the pathogen. The next time the same antigen appears in the body, as part of a new infection, the immune system is prepared to mount a rapid and overwhelming response.

VAAST™ = Vector-Adjuvant-Antigen Standardized Technology

Modular Vaccine Creation

The Vaxart tablet vaccine is composed of three basic elements:

• The vector: the Ad5 delivery vehicle that carries the DNA “payload” to the gut
• The antigen: the pathogen protein designed to trigger the targeted immune response
• The adjuvant: a “booster” molecule that stimulates and adds to the immune response

By using the same vector, but with different antigens, Vaxart has designed a modular, scalable and standardized approach to vaccine development.

• With this system, we can support the rapid development of numerous vaccines against established targets, as well as against new and emerging pathogens.
• We can achieve important synergies – we can use the same manufacturing processes for all of our vaccines.