Therapeutic Vaccines
What is a therapeutic vaccine? A therapeutic vaccine is a relatively new concept since it is used for treatment of a disease rather than for preventing it. A therapeutic vaccine stimulates the immunological system of the host in situations in which it is insufficiently capable to develop an effective response to the cause of the disease. Immunitor products are orally administered with a site of action in the mucosa of the human gut.

Oral Delivery
Today practically any biotech company can make a vaccine. However, most vaccines are delivered by needle injection. Companies that have developed novel vaccine delivery methods have became a success story. For example, Chiron bought Powderject’s needle-less technology for USD$880 million (Link to article); Medimmune acquired Aviron’s spray Flumist flu vaccine for $1.5 billion (Link to article). These examples indicate the emphasis on new delivery technologies and increased interest of major vaccine companies to purchase such a technology at high price. Several start-up companies have been or are developing new vaccine deliveries mostly as a patch, spray, or capsule. However, except for a few efforts, most companies are still in the early stages of development. In contrast, Immunitor is the only company to have successfully developed an oral vaccine available as a simple pill.

Mucosal Immunity
Almost all infectious agents (viruses, bacteria, fungi, and parasites) enter the host through mucous membranes. Therefore, mucosal immunity, rather than systemic, is essential to maximally protect against naturally-transmitted pathogens. Oral vaccine delivery could confer local immunity, not only at the site of delivery, but on the surface of other mucosal membranes, and, eventually induce systemic immunity as well.

Alloimmunization
Alloimmunization refers to an immune response generated in an individual of one species by an alloantigen from a different individual of the same species. In 1796 Edward B. Jenner – the official founder of modern vaccinology –inoculated James Phipps, son of his gardener, with liquid from the cowpox blisters on  the hand of Sarah Nelmes, a milkmaid who had caught cowpox from a cow named Blossom. The subsequent generations of vaccinologists made emphasis on the fact that Jenner’s vaccine contained poxvirus but completely ignored that the preparation also contained alloantigens, and that later on it even contained xenoantigens - when the vaccine was harvested from the skin of calves. Under certain circumstances, e.g., immunization with small doses of alloantigen, a state of immune tolerance is produced.

Immune Tolerance
The early indications that oral antigen exposure can lead to immune tolerance and suppression of the systemic immune response to subsequent antigenic challenge can be found in seminal works published in late 19th and early 20th centuries by Milton J. Rosenau and John F. Anderson (credited for the foundation of what is now known as the NIH and FDA), and Alexandre Besredka, the successor of Ilya (Elie) Metchnikoff, at the Institute Pasteur. This phenomenon was “re-discovered” in 1960’s when immunology methods became more sophisticated. Even today the phenomenon of tolerance has not been fully elucidated. In some situations oral vaccination benefits from the phenomenon of tolerance, particularly in diseases characterized by overdriven immune response, e.g., allergies, arthritis, multiple sclerosis, diabetes, etc. Some viral and bacterial infections also provoke inflammatory immune reaction. Theoretically, prophylaxis and treatment of those infections could benefit from tolerance induction. Immunitor has demonstrated this through the company’s studies of oral vaccination against HIV, hepatitis, influenza, and tuberculosis with remarkable therapeutic results and potential prophylactic benefit.