Disease Information

In today's day and age, protection against potential bioterrorism agents is crucial for the safety of the military and the general public. Inviragen aims to develop a vaccine that defends against two dangerous agents of bioterrorism – plague and smallpox.

The bacterium that causes plague, Yersinia pestis, is usually transmitted by biting fleas. However, an aerosol release of Y. pestis could cause the dangerous pneumonic (or respiratory) form of the disease.

As with the dengue and West Nile vaccine programs, Inviragen is using a clinically-proven, safe vaccine vector to develop a vaccine to protect against Y. pestis. The vector is an attenuated vaccinia virus, termed modified vaccinia Ankara (MVA).

MVA was demonstrated to be safe in several studies, including vaccination studies in immune-compromised mice, immune-compromised and infant macaques, and in over 120,000 individuals during the smallpox eradication program. As a result of its efficacy and safety, MVA is considered a potential replacement smallpox vaccine. MVA can be genetically manipulated to express other infectious disease antigens Additionally, several vaccine clinical trials are using such recombinant MVA (rMVA) viruses as components of HIV or malaria vaccines.

Through its expertise in the field of poxvirus engineering, Inviragen is working to construct MVA-based vaccines that optimally express multiple protective antigens from Y. pestis. A Small Business Biodefense Program grant from the National Institute of Allergy and Infectious Diseases (NIAID) supports the development and testing of Inviragen's novel MVA/plague vaccine constructs. Using these funds, vaccines will be constructed and their safety and efficacy will be tested in mouse models of aerosolized Y. pestis. These MVA/plague constructs will be administered intranasally to generate immune responses in the mucosal tissues where respiratory pathogens begin their attack. Inviragen believes mucosal immune responses will provide more rapid and potent protection against an aerosolized plague bioweapon.

Using recombinant MVA as a platform for next generation biodefense vaccines provides a distinct advantage: MVA also generates protective responses against smallpox. Overall, Inviragen's MVA/plague vaccine offers protection against two high-threat respiratory bioweapons – plague and smallpox – through a safe and simple intranasal administration.