Keystone, Colorado
April 9, 2002

-- Successful expression of SIV sub unit vaccine
-- Important step to make a future edible AIDS vaccine

ProdiGene, Inc., a leader in the development and manufacturing of recombinant proteins in transgenic plant systems, announced here today at the Keystone Symposia, that it successfully expressed a sub unit vaccine in maize that is expected to produce an immune response to simian immunodeficiency virus (SIV), the primate equivalent to HIV which causes AIDS in people. The research is funded by an Innovation Grant program from the NIH Institute of Allergy and Infectious Disease's Office of AIDS Research (NIH/NIAID/DAIDS). The objective of the program is to develop a source of SIV gp120 protein, a key protein in AIDS research, as well as to establish a potential oral delivery system for an AIDS vaccine.

ProdiGene has successfully expressed SIV gp120 in its transgenic plant system, which now provides a source of the protein to be used in AIDS research. Additionally, ProdiGene scientists will begin animal studies this spring to confirm that ingesting the vaccine will induce an immune response against the virus. This constitutes a key stepping stone for moving into the expression of an HIV vaccine in a transgenic plant system. ProdiGene's long- range plan is to develop an oral delivery method for an AIDS vaccine.

"The search for an AIDS vaccine continues to advance aggressively," remarked Michael Horn, Ph.D.,  Senior Research Scientist and Project leader at ProdiGene. "Once we have the vaccine in hand however, we must be able to make it readily accessible to the populations that are in such dire need. ProdiGene's system promises to provide the edible, highly-scalable and cost effective vaccine option that can meet this demand."

Developing an edible vaccine against HIV is particularly critical because it has reached epidemic proportions, particularly in Sub-Saharan Africa and South and Southeast Asia, which together have more than one-half of all AIDS victims worldwide. In these areas, standard vaccines are not feasible because they lack the infrastructure to provide trained healthcare personnel and equipment, as well as the refrigeration, necessary for traditional injected vaccines.

ProdiGene, which announced receipt of the grant in November 2000, is working with a protein known as gp120, which is found on the surface of the SIV and HIV virus. Although gp120 may not be the ultimate vaccine used to develop an effective oral AIDS vaccine, expression of the protein using ProdiGene's technology helps provide the vaccine delivery system proof-of-concept sought by the NIH.

About AIDS and Vaccines

AIDS continues to be a worldwide health crisis. As of the end of 2001, an estimated 40 million people worldwide -- 37.2 million adults and 2.7 million children younger than 15 years -- were living with HIV/AIDS. More than 70 percent of these people (28.1 million) live in Sub-Saharan Africa; another 15 percent (6.1 million) live in South and Southeast Asia.

Sub unit vaccines work by introducing small quantities of protein from a virus into the body, which encourage the production of antibodies. When a real infection hits, these antibodies are already in place to fight off the virus. ProdiGene's vaccines are antigens (a specific type of protein) produced using its proprietary transgenic plant technology and then delivered using its patented edible vaccine platform. Edible vaccines produced using the Company's technologies could be dosed in an edible form, and are thus easy to administer. Oral vaccines are not only more convenient than alternate forms of administration, such as injection, but are also less costly to administer and can help make vaccination more widely available, particularly in developing countries.

About ProdiGene

ProdiGene, headquartered in College Station, Texas, is a private biotechnology company that is developing and manufacturing industrial and pharmaceutical proteins from a transgenic plant system. ProdiGene, as the first and only company to produce and market a recombinant protein from a transgenic plant system, is well positioned to capitalize on the opportunities in the large and expanding recombinant protein markets. The Company has collaborations with leading biotechnology and pharmaceutical companies including Genencor, Eli Lily and Avant Immunotherapeutics.