Vaccines that are eaten, not injected
In what may be a most significant development in the effort to produce vaccines that can be eaten rather than injected, ProdiGene (College Station, TX) has received a patent for a process that uses plants to develop oral vaccines that can immunize humans and animals against viral diseases. ProdiGene is a biopharmaceutical and industrial protein company.
ProdiGene's system (U.S. Patent #6,136,320) creates pharmaceutical products in plants for human and animal consumption, according to ProdiGene president and CEO John Howard. While traditional injected vaccines require serious manufacturing and downstream processing, plant-based vaccines reduce production costs considerably and are eaten, which reduces costs associated with both making and taking.
"Plant-based vaccines have a number of advantages over injectable vaccines," said Carol O. Tacket of the Center for Vaccine Development at the University of Maryland. "[Oral, plant-based] vaccines will be well-tolerated, inexpensive to produce and eliminate the costs of sterile needles and syringes, and could potentially be produced near the target population for vaccination."
Not just for humans
Edible vaccines could also revolutionize the animal vaccine industry, according to Ian Tizard, professor of immunology at the Texas A&M University College of Veterinary Medicine. "In animal agriculture, much of the cost of animal vaccination is a result of the need to handle individual animals," Tizard stated. "Thus the ability to vaccinate large numbers of animals without having to handle them individually, is much less stressful for the animals and much less expensive for the farmer or rancher. In addition, one major problem facing producers is that of injection-site lesions, including abscesses and other lesions that are apt to develop at sites where vaccines are injected. These have to be removed when animals are processed and spoil significant quantities of meat."
ProdiGene's vaccine technology uses advanced techniques from biotechnology to create plant-based protein products that immunize against viral disease. The process involves insertion of genes from viruses into the genome of a plant that instructs the plant to produce an antigen for a specific disease. The resulting genetically-enhanced plant can be used as an immunizing feedstock for animals or introduced into food products for human consumption. Safety concerns are minimized because plants are incapable of harboring human or animal pathogens.
Among the benefits of the delivery system are:
- Vaccines can be delivered orally rather than by injection,
- Vaccines may not require a health care professional to administer, and
- Products can be stored and transported as foods, without special conditions such as refrigeration.
ProdiGene has received patents for hepatitis B in humans and transmissible gastroenteritis virus (TGEV), a highly infectious disease in swine. The company has demonstrated the efficacy of its TGEV vaccine in clinical trials.
For more information, contact Dane Hammes of Prodigene at 409-690-8537.
Edited by Angelo DePalma
Managing Editor, Drug Discovery Online and Pharmaceutical Online