In countries where rice is a major part of the diet, many children go blind. The production of vitamin A is controlled by enzymes. We can insert genes to control these reactions. Golden rice, created by a group of Swiss scientists, contains beta-carotene. It will be important for nutrition for developing nations.
Vaccination can control disease.
The active agents can be inserted into a food plant, such as bananas. Then people will get protection by eating the vaccine. We can insert a rust-resistance gene to give the crop plant a defence. This reduces the need for sprays and maintains productivity. Salinity is increasing in our soils.