Argentina - Banning the foot and mouth disease virus soon with a promising vaccine

Researchers from Buenos Aires recently succeeded in developing a prototype vaccine for the Foot and Mouth Disease Virus in genetically modified plants. In many cases, the development of vaccines in transgenic plants is a highly efficient, inexpensive, and also environmentally friendly way to produce a vaccine when compared to conventional methods. Due to the reduced production costs, low, middle and high income countries stand to profit. Edible vaccines which are produced by molecular farming also offer the advantages of oral administration instead of injection, plus they are more stable and offer the possibility of dry freezing. This is another big advantage for developing countries where refrigerators are too expensive, or often not available. So far vaccines for six infectious diseases (Hepatitis B, Diarrhoea, Norwalk virus, Rabies, Measles, respiratory syncytial virus) have been successfully expressed in plants and administered orally to animals or humans. A seventh may not be far off. The Foot and Mouth Disease (FMD) virus causes a disease which affects milk and meat producing domestic animals. The 2001 FMD epidemic in the UK cost about 9 billion US$ and about 6 million animals had to be slaughtered. There are vaccines for the FMD virus available today, but the production of the vaccine is expensive and carries a risk to animals. That is why the work of Dr. M.J. Dus Santos and her team at the Instituto de Virología S.Rivenson in Buenos Aires, Argentina is so important. Their goal was to find a FMD vaccine that could be expressed in an edible plant. Vaccines developed in transgenic plants carry no risk to the animals and can be much less expensive. Dr. Santos’ work is unique, because previous vaccines have concentrated on using simple, recognizable structures. But now for the first time Dr. Dus Santos and her team were able to produce a complex antigenic structure (vaccines are composed of antigens, which lead to an antibody reaction of our immune system) of a protein, called FMDV VP1 polyprotein, from the FMD virus. For their experiments they produced transgenic alfalfa plants expressing the FMDV VP1 polyprotein with the help of Agrobacterium tumefaciens, a microbe which is used to transfer genetic material into plants. Once Dr. Dus Santos was able to harvest enough of the transgenic alfalfa varieties, the vaccine component was separated and used in initial studies with mice. After administering mice the oral vaccine, Dr. Dus Santos laboratory showed that all the mice produced a good immune response, which normally indicates protection against future infections. To test this, Dr. Dus Santos team infected the mice with the FMD virus. Much to their content, none of the mice became infected. From the development of a vaccine against the FMD virus in transgenic plants all countries with an important animal farming economy stand to profit. Of course it has a very high importance for a developing country, such as Argentina, where livestock is an important asset to the its economy. Dr. Dus Santos’ new vaccine should soon become an inexpensive and safe method to protect Argentina’s and the world’s livestock against FMD. Silke Luetzelschwab is a Molecular Biologist and a Scientific Writer for Checkbiotech. Maria J. Dus Santos et al. Development of transgenic alfalfa plants containing the foot and mouth disease virus structural polyprotein gene P1 and its utilization as an experimental immunogen. Vaccine, 23 (2005), p. 1838-1843