Will the Chimigen Vaccine Stop Bird Flu, Anthrax and Hepatitis?

We interviewed Dr. Rajan George, Adjunct Faculty of the University of Alberta’s Pharmacy and Pharmaceutical Sciences Department. Dr. George is also Vice President of Research and Development for the Division of Infection Diseases of ViRexx Medical Co. As part of the team of University of Alberta scientists, a therapeutic vaccine is now being developed which may inoculate against Hepatitis, Anthrax and Avian Flu H5N1. The team of scientists includes internationally renowned Dr. Lorne Tyrrell, former Dean of Medicine at the University of Alberta, and Dr. Antoine Noujaim, Professor Emeritus of the University of Alberta.

All three scientists are affiliated with ViRexx Medical Corp. On March 31st, the company announced it had entered into research collaboration with Defence Research and Development Canada – Suffield (DRDC Suffield) to carry out research to evaluate ViRexx’s proprietary Chimigen(TM) vaccine platform for biodefense applications. On April 6th, the company announced it had recruited procurement advocate Frank Rapoport of McKenna Long & Aldridge to pursue acquisitions of development contracts from the U.S. Department of Defense and NIH with a particular focus on the potential of the Chimigen(TM) technology in addressing biodefense and pandemic threats. The company cited two of major targets would be, but not limited to, H5N1 avian flu and anthrax.

Interviewer: Can you describe ViRexx Medical’s Chimigen(TM) therapeutic vaccine?

Dr. Rajan George: Chimigen therapeutic vaccine is used to produce immune responses in a host against infections which are difficult to produce immune responses, by targeting the vaccine to dendritic cells. The Chimigen platform can be extended to develop therapies for difficult-to-treat chronic infectious diseases.

Interviewer: Does that mean the Chimigen platform can be used to treat any infectious disease?

Dr. Rajan George: Yes, except in cases where the immune system is non-functional, as in the case of HIV.The Chimigen platform can be used to produce either a therapeutic vaccine or a prophylactic vaccine. This depends on the disease target and the antigen plugged into the platform. Some antigens have a use in treating infection, while others have a use in preventing an infection. Either one would be targeted to the dendritic cells. The therapeutic vaccine generates a cytotoxic T cell response. A prophylactic vaccine would generate a B cell response and antibody production.

Interviewer: From the way you’ve described the Chimigen(TM) vaccine, it appears potentially useful for many applications beyond Hepatitis B and C. How broad are the applications?

Dr. Rajan George: We should be able to use this platform for cancer therapy, depending upon the cancer antigen we use. We can plug in a specific cancer antigen into this platform, and the vaccine targeted to dendritic cells. The dendritic cells would process and present the right antigen, then generating immune responses (T &B cell) against the cancer. We are also evaluating some bioterrorist viruses, the biological weapons terrorists would use. We just started a project to look at one of those viruses to see if we can come up with the prophylactic vaccines to prevent diseases that would be caused by organism that could be used in bioterrorism

Interviewer: Would the Chimigen(TM) vaccine be effective as a prophylactic against avian flu, H5N1?

Dr. Rajan George: It could work for bird flu if we just plugged in the bird flu antigen into the platform. Then we can use it as a prophylactic. It generates antibody to generate B-Cell response. You can produce a prophylactic vaccine using this platform. The Chimigen(TM) platform is quite adaptable.

Interviewer: How high is your confidence level in producing a prophylactic vaccine for the avian flu virus?

Dr. Rajan George: My thinking is that it is quite high. I think very highly of having a vaccine like that. But, the ultimate proof has to come from humans. Our HepaVaxx B clinical trial will give us a lot of information on how the technology really works. Until then, our optimism is based on laboratory results.

Interviewer: Can you describe what comprises the Chimigen platform?

Dr. Rajan George: The platform has two components. The first one is from the infectious agent. The second component is from a murine monoclonal antibody. Part one is fused with a fragment of part two by recombinant technology to produce a new entity, the Chimigen(TM) vaccine. We are recombining one thing with another. We have a virus which has certain antigens. We take one of those, and we produce a recombinant molecule with the fragment we have taken from a murine monoclonal antibody. Chimigen is the term we came up with to include the meaning of the full phrase, chimeric antigen. Chimeric means it comes from two different sources. We put them together and create a new molecule. One is from the virus. The other one is from the mouse, the monoclonal antibody. Now we have by recombinant methods produced a protein which is a chimeric protein. That’s the Chimigen(TM) vaccine.

Interviewer: How do you produce such a flexible vaccine, one that appears capable of treating nearly any infection?

Dr. Rajan George: To produce a Chimigen(TM) vaccine to treat nearly any infection, we start with an antigen (protein) from the infectious agent. We fuse it with a fragment called Fc of a mouse monoclonal antibody. This is done using recombinant methods. We end up with a new protein. This protein is made in a cell culture of commercially available insect cells. The protein is produced by the insect cells. From the culture, we purify this particular protein that we made. The insect cell system is just a tool. By virtue of its production in insect cells, the protein attains special properties which are useful in generating better immune responses.

Producing this protein in insect cells gives it some very peculiar properties, which are different from our own mammalian proteins. Once we have it coming out of the cell, we purify it and make it really pure. Now we have a protein with the virus antigen murine monoclonal antibody with modified properties. This is a totally new entity.

Interviewer: What do you mean when you say, “useful in generating better immune responses”?

Dr. Rajan George: When a person has a chronic virus infection, his or her body ignores the virus and associated proteins. The body treats the virus as part of itself. The body does not recognize this virus as something foreign to it. Therefore the immune system does not attack the virus. But, by combining the virus antigen with a foreign protein such as the murine antibody fragment, the whole chimeric protein now is recognized by the body’s immune system as “foreign,” different from something of its own. In essence, this is a re-education of the immune system to switch its recognition of the virus from “self” to “foreign”.

Interviewer: From where did the scientific model come, and does it have similarities to another ViRexx Medical product, OvaRex MAb