Who is doing what with edible vaccines?

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http://www.biosafety-info.net/article.php?aid=71

Who is doing what with edible vaccines? * The first human clinical trial of an edible vaccine took place in 1997, when volunteers ate raw potatoes genetically engineered against diarrhoea-causing E coli. Ten of the 11 volunteers who received the vaccine had fourfold rises in serum antibodies. * Researchers from the Boyce Institute (BTI) at Cornell University conducted another clinical trial of an edible vaccine in 1999. Potatoes containing the Norwalk virus (which causes vomiting and diarrhoea) fed to volunteers elicited an immune response in 19 out of 20 subjects. BTI researchers are attempting to engineer vaccines into bananas and have produced powdered tomatoes that carry Norwalk virus DNA. BTI scientists have also been awarded a Rockefeller Foundation grant - $58,000 for three years - to collaborate with Mexican researchers at the Mexican health agency, CINESTAV. * Prodigene and Stauffer Seeds (a spin-off of Staffer Chemical, formerly a division of Novartis) have conducted clinical trials on pigs using an edible vaccine for transmissible gastroenteritis virus (TGEV) expressed in corn, and are developing a Hepatitis B vaccine for humans. * The US' Large Scale Biology Corporation is developing a patient-specific non-Hodgkin's lymphoma vaccine in plants. Current methods for making the custom vaccine require up to a year to produce vaccine for patient use; LSB thinks its production process could reduce that time to 6-8 weeks. * Under license from Mycogen, the UK's Axis Genetics was developing an oral hepatitis B booster vaccine in edible plants, and had plans for Norwalk virus and diarrhoea. Axis went out of business in 2000, saying that protests over bioengineered food had scared off investors. Myocgen continues to work on edible vaccines for animals. * Under license from Groupe Limagrain, Meristem Therapeutics has developed industrial processes for the large-scale production of recombinant therapeutic proteins in plants. Plants including tobacco, corn, potato and rape seed are being used as bioreactors for the production of enzymes, antibodies, and vaccines. * The Scripps Research Institute is working on an edible HIV vaccine. Initial success has been reported in splicing amino acids from HIV into the cowpea mosaic virus (CPMV). When inoculated with CPMV, cowpea plants reproduce HIV. * Scientists in Poland working with the US' Jefferson University have tested a hepatitis B vaccine contained in lettuce on human subjects. * In Melbourne, Australia, CSIRO has grown a measles-fighting tobacco plant and has begun pilot studies with oral plant-based vaccines for malaria and HIV. --------------------------------------------------------------------------------------------------------- Genes going wildGenetic engineering is inherently hazardous because it depends on developing gene transfer vectors (carriers) specifically designed to cross wide species barriers. It promotes the transfer of genes horizontally across species, instead of vertically within species by inheritance. It is also increasingly designed to overcome the species' defence mechanisms which degrade or inactivate foreign genes. It is still a very crude science, with genes being inserted at random points in the host's genetic material (genome), rather than being carefully pinpointed as happens in traditional breeding. For these and other reasons, genetic engineering destabilises the genomes of its plant and animal hosts, and the effects ricochet through the neighbouring ecosystem. There is growing evidence that by facilitating horizontal gene transfer and recombination, genetic engineering may be contributing to the emergence and re-emergence of infectious, drug-resistant diseases. Edible vaccines (even subunit vaccines) will always entail the ingestion of recombinant viral genetic material, and hence pose considerable risks to the environment and health. Edible subunit vaccines are likely to be less dangerous than those that may be produced using genetically modified viruses and viruses used as vectors (carriers) for the vaccine. But they still involve the insertion of foreign genes into the plants and the implications thereof. Genetically tweaking the pathogen to reduce its potency is even more risky. It has been demonstrated that minor genetic changes in, or differences between, viruses can result in dramatic changes in host spectrum and disease-causing potentials. According to Terje Traavik of the Norwegian Institute of Gene Ecology, 'For all these vaccines, important questions concerning effects on species other than the targeted one are left unanswered so far.' There are also considerable risks related to the possibility of a genetically engineered vaccine virus engaging in recombinations with naturally-occurring relatives. New viruses resulting from such events 'may have totally unpredictable characteristics with regard to host preferences and disease-causing potential,' says Traavik. Naked DNA vaccines, which comprise the genes of the pathogen without the virus 'shell,' are perhaps the most risky. These short pieces of DNA are readily taken up by cells of all species, and may become integrated into the cell's genetic material. Unlike chemical pollutants which dilute out and degrade over time, these small DNA fragments can be taken up by cells and multiply and mutate indefinitely. They are known to have significant and harmful biological effects, including cancers in mammals. Upon release or escape to the wrong place at the wrong time, horizontal gene transfer with unpredictable biological and ecological effects is a very serious, and as yet unregulated, hazard.Sources: T Traavik (1999), 'Environmental Effects of Genetically Engineered Vaccines,' Third World Network Online, http://www.twnside.org.sg/title/vaccine.htm; Mae-Wan Ho et al (1999), 'Unregulated Hazards of Naked and Free Nucleic Acids', ISIS report for the Third World Network. http://www.i-sis.org/naked.shtml

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http://www.biosafety-info.net/article.php?aid=71

Who is doing what with edible vaccines? * The first human clinical trial of an edible vaccine took place in 1997, when volunteers ate raw potatoes genetically engineered against diarrhoea-causing E coli. Ten of the 11 volunteers who received the vaccine had fourfold rises in serum antibodies. * Researchers from the Boyce Institute (BTI) at Cornell University conducted another clinical trial of an edible vaccine in 1999. Potatoes containing the Norwalk virus (which causes vomiting and diarrhoea) fed to volunteers elicited an immune response in 19 out of 20 subjects. BTI researchers are attempting to engineer vaccines into bananas and have produced powdered tomatoes that carry Norwalk virus DNA. BTI scientists have also been awarded a Rockefeller Foundation grant - $58,000 for three years - to collaborate with Mexican researchers at the Mexican health agency, CINESTAV. * Prodigene and Stauffer Seeds (a spin-off of Staffer Chemical, formerly a division of Novartis) have conducted clinical trials on pigs using an edible vaccine for transmissible gastroenteritis virus (TGEV) expressed in corn, and are developing a Hepatitis B vaccine for humans. * The US' Large Scale Biology Corporation is developing a patient-specific non-Hodgkin's lymphoma vaccine in plants. Current methods for making the custom vaccine require up to a year to produce vaccine for patient use; LSB thinks its production process could reduce that time to 6-8 weeks. * Under license from Mycogen, the UK's Axis Genetics was developing an oral hepatitis B booster vaccine in edible plants, and had plans for Norwalk virus and diarrhoea. Axis went out of business in 2000, saying that protests over bioengineered food had scared off investors. Myocgen continues to work on edible vaccines for animals. * Under license from Groupe Limagrain, Meristem Therapeutics has developed industrial processes for the large-scale production of recombinant therapeutic proteins in plants. Plants including tobacco, corn, potato and rape seed are being used as bioreactors for the production of enzymes, antibodies, and vaccines. * The Scripps Research Institute is working on an edible HIV vaccine. Initial success has been reported in splicing amino acids from HIV into the cowpea mosaic virus (CPMV). When inoculated with CPMV, cowpea plants reproduce HIV. * Scientists in Poland working with the US' Jefferson University have tested a hepatitis B vaccine contained in lettuce on human subjects. * In Melbourne, Australia, CSIRO has grown a measles-fighting tobacco plant and has begun pilot studies with oral plant-based vaccines for malaria and HIV. --------------------------------------------------------------------------------------------------------- Genes going wildGenetic engineering is inherently hazardous because it depends on developing gene transfer vectors (carriers) specifically designed to cross wide species barriers. It promotes the transfer of genes horizontally across species, instead of vertically within species by inheritance. It is also increasingly designed to overcome the species' defence mechanisms which degrade or inactivate foreign genes. It is still a very crude science, with genes being inserted at random points in the host's genetic material (genome), rather than being carefully pinpointed as happens in traditional breeding. For these and other reasons, genetic engineering destabilises the genomes of its plant and animal hosts, and the effects ricochet through the neighbouring ecosystem. There is growing evidence that by facilitating horizontal gene transfer and recombination, genetic engineering may be contributing to the emergence and re-emergence of infectious, drug-resistant diseases. Edible vaccines (even subunit vaccines) will always entail the ingestion of recombinant viral genetic material, and hence pose considerable risks to the environment and health. Edible subunit vaccines are likely to be less dangerous than those that may be produced using genetically modified viruses and viruses used as vectors (carriers) for the vaccine. But they still involve the insertion of foreign genes into the plants and the implications thereof. Genetically tweaking the pathogen to reduce its potency is even more risky. It has been demonstrated that minor genetic changes in, or differences between, viruses can result in dramatic changes in host spectrum and disease-causing potentials. According to Terje Traavik of the Norwegian Institute of Gene Ecology, 'For all these vaccines, important questions concerning effects on species other than the targeted one are left unanswered so far.' There are also considerable risks related to the possibility of a genetically engineered vaccine virus engaging in recombinations with naturally-occurring relatives. New viruses resulting from such events 'may have totally unpredictable characteristics with regard to host preferences and disease-causing potential,' says Traavik. Naked DNA vaccines, which comprise the genes of the pathogen without the virus 'shell,' are perhaps the most risky. These short pieces of DNA are readily taken up by cells of all species, and may become integrated into the cell's genetic material. Unlike chemical pollutants which dilute out and degrade over time, these small DNA fragments can be taken up by cells and multiply and mutate indefinitely. They are known to have significant and harmful biological effects, including cancers in mammals. Upon release or escape to the wrong place at the wrong time, horizontal gene transfer with unpredictable biological and ecological effects is a very serious, and as yet unregulated, hazard.Sources: T Traavik (1999), 'Environmental Effects of Genetically Engineered Vaccines,' Third World Network Online, http://www.twnside.org.sg/title/vaccine.htm; Mae-Wan Ho et al (1999), 'Unregulated Hazards of Naked and Free Nucleic Acids', ISIS report for the Third World Network. http://www.i-sis.org/naked.shtml

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