Scientists have used transgenics (that is removing genetic material from one species and adding it to another) to create vaccines. In one very good example, they introduced a human protein into a banana, potato and other plants to create an edible version of the vaccine that treats cholera.
A similar event happened when they introduced human DNA into tobacco plants to create a flu vaccine.
This cross breeding of human to plant DNA has benefited human kind.
Although we regularly eat plant based foods, is there risk for medicines created in this way?