dEbate Response To:
Eat your corn flakes—and get vaccinated?  [Article] [Submit a response to this article]
AIDScience Vol. 2, No. 7, April 2002

Published dEbate responses:

[Read dEbate]Edible AIDS vaccine or dangerous biological agent?
   Veljko Veljkovic and Mae-Wan Ho (25 April 2002)

[Read dEbate]Edible AIDS vaccine or dangerous biological agent? Response.
   John Howard (1 May 2002)

Edible AIDS vaccine or dangerous biological agent? 25 April 2002

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Veljko Veljkovic, Laboratory for Multidisciplinary Research, Institute of Nuclear Sciences, P.O. Box 522, 11001 Belgrade, Yugoslavia. E-mail:
Mae-Wan Ho, Director, Institute of Science in Society, P.O. Box 32097, London NW1 0XR, United Kingdom. E-mail:

Results of laboratory and clinical research performed during last 15 years strongly suggest that AIDS vaccines based on gp120 cannot be effective and, more importantly, may not be safe (1, 2).

A biological warfare agent could be designed with the following characteristics: 1) possess a slow-acting pathogenic component to allow the spread of disease over a long period of time, as to escape detection; 2) possess an antigenic determinant enabling the biological agent to breach the host immune defence; 3) have the ability to transfer the gene encoding the pathogenic determinant to other microorganisms and plants, with the possibility of generating new deadly pathogens; and 4) ability to attack the immune system of the host, making it vulnerable to other infectious and chronic diseases including cancer. The evidence reviewed in a recent article (1) indicates that at least some of these characteristics are satisfied by HIV-1 gp120.

In addition, introducing HIV-1 gp120 into corn could lead to widespread contaminating of our food supply, as even land races of corn growing in remote regions of Mexico may have become contaminated (3), although this recent finding is now in dispute (4, 5). The major controversy surrounding the finding is whether the transgenic constructs were "fragmenting and promiscuously scattering throughout genomes" of the land races. That would be indicative of horizontal gene transfer and recombination, mostly likely mediated by the known recombination hotspot in the cauliflower mosaic virus (CaMV) promoter use in many transgenic constructs (6-8). At stake is the health of human beings and all other organisms in the food chain. As the gp120 gene is also known to possess recombination hotspots, there may be opportunities for horizontal gene transfer and recombination to create new pathogens, considering that some 99% of the bacteria that exist cannot be cultured, and their potential for causing diseases are hence unknown.


1. V. Veljkovic, et al., Vaccine 19, 1855 (2001). PubMed.
2. H. Kohler, S. Muller, V. Veljkovic, AIDScience 2, 5 (2002). Available online.
3. D. Quist, I. H. Chapela, Nature 414, 541 (2001). PubMed.
4. M. Metz, J. Futterer, Nature 416, 600 (2002). PubMed.
5. N. Kaplinsky, Nature 416, 601 (2002). PubMed.
6. M. W. Ho, A. Ryan, J. Cummins, Microbial Ecology in Health and Disease 11, 194 (1999).
7. M. W. Ho, A. Ryan, J. Cummins, Microbial Ecology in Health and Disease 12, 6 (2000).
8. M. W. Ho, A. Ryan, J. Cummins, Microbial Ecology in Health and Disease 12, 189 (2000).

Edible AIDS vaccine or dangerous biological agent? Response. 1 May 2002

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Author: John Howard, chief scientific officer and founder, ProdiGene, Inc. E-mail:

These two scientists bring up very good points; however, they are misdirected with relation to the research that is ongoing with the edible AIDS vaccine.

First, the scientists correctly point out that gp120 has not been an effective vaccine on its own. While this is a very valid point, it is not intended that gp120 alone would be the vaccine. The research is targeted toward a delivery system where people can use the vaccine of choice but deliver it in an edible form. Gp120, therefore, is used only as a proof of principle that these can be expressed and delivered efficaciously. The exact vaccine for AIDS may involve gp120, along with other proteins. The work that was done at ProdiGene was not to imply that this was the final answer, only a step in developing a better delivery system.

Second, the two scientists raised the concern that this could lead to a widespread contamination of the food supply. While food safety issues have been brought to the attention of the public by recent reports, as the scientists correctly point out, this is in dispute. However, what is missing for this case is the fact that the genetically modified corn grown under dispute was unregulated. No contained measures were employed. The assumption that these new vaccines or pharmaceuticals would be released into the environment without any controls is unfounded. Pharmaceuticals made from corn are tightly regulated, as well as other food organisms that are used to make pharmaceuticals. Under these tightly regulated and contained conditions, many food organisms can be used as biofactories without getting into the food chain; thereby, providing an extremely safe product, and at the same time minimizing the risks. As an example, yeast can be used for making beer or bread but is also used to make pharmaceuticals, yet the conditions for growing such are vastly different.

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