Generex Biotechnology Corporation's, wholly owned immunotherapeutics subsidiary, Antigen Express, Inc has made proposals for co-development of the Antigen Express novel H5N1 avian influenza vaccine in China following a trip to Beijing by Dr. Minzhen Xu, the Antigen Express vice-president of Biology.

According to a company release, the vaccine technology being employed at Antigen Express for the potentially pandemic avian influenza is the same as that for its novel immunotherapeutic cancer vaccine currently in clinical trials.

"The basis of this technology lies in identifying portions of a specific disease-associated protein that are capable of stimulating T-helper cells which are subsequently modified to augment their vaccine potency," explained Dr. Xu. "T-helper cells play a critical role in generating an immune response to a novel foreign agent, directing other immune cells against that threat, and in establishing immunological 'memory' of that agent. Once these cells are stimulated, it is much easier to mount an effective response against an agent such as the H5N1 influenza virus."

Antigen Express has extant collaborations in China focusing on SARS and a novel immunotherapy strategy for patients with acute myeloid leukaemia.

"These relationships provide a convenient platform for expanding into avian influenza in China. The danger posed by avian influenza in China is more acute, given the recent outbreaks of the H5N1 strain in birds there, and they face the same supply limitations on traditional vaccines as are faced throughout the world. Furthermore, vaccinating people close to hot spots of H5N1 outbreaks is recognised as the best way to control a possible pandemic," said Dr. Eric von Hofe, president of Antigen Express.

Current estimates are that the world capacity per year for production of H5N1 vaccine by traditional methods would protect less than 40 million people.

The release further states that scientists at Antigen Express are developing a vaccine for the potentially pandemic Asian bird flu utilising highly conserved fragments of the H5 protein to stimulate potent T-helper cell activity. The H5 fragments are modified using a portion of an immunoregulatory protein (termed Ii-Key) that greatly facilitates their ability to stimulate T-helper cell responses specific to the H5N1 strain. The vaccine peptides have been selected for their likelihood of being both potent and active in more than 90% of the population. This technology has the advantage of being applicable to any novel agent or protein once one has sequence information. As vaccine peptides are manufactured by entirely synthetic means they can be produced rapidly, relatively inexpensively, and in large quantities (hundreds of millions of doses).

Generex is engaged in the research and development of drug delivery systems and technologies. Generex has developed a proprietary platform technology for the delivery of drugs into the human body through the oral cavity (with no deposit in the lungs).