Kim and colleagues' aim was to develop a plant-derived vaccine against Alzheimer's disease, since beta-amyloid is toxic to animal cells. Tomatoes are an attractive candidate as a vaccine carrier because they can be eaten without heat treatment, which reduces the risk of destroying the immune stimulation potential of the foreign protein. The researchers inserted the beta-amyloid gene into the tomato genome and measured the immune responses to the tomato-derived toxic protein in a group of 15-month-old mice.

They immunized the mice orally with the transgenic tomato plants once a week for three weeks, and also gave the mice a booster seven weeks after the first tomato feed. Blood analyses showed a strong immune response after the booster, with the production of antibodies to the human foreign protein.