Vaccines and Hormones Vaccines Traditionally vaccines are manufactured using animals. Weakened or dead bacteria that cause diseases are injected into an animal. The animal’s immune system produces defensive chemicals called antibodies, which are later, removed as a vaccine for human use. As you can see, this method the costly and low in productivity. With GE, vaccines can be made quickly, cheaply, in large quantities and without the need to use animals. By the GE method, DNA is removed from the bacterium that causes the disease, and the gene that carries the code for a protein is cut out and inserted into the DNA of yeast cells. The yeast cells produce the proteins, which can then be used in the vaccine. Growth hormones Throughout our lives, tiny amounts of human growth hormone are released by the pituitary gland in the brain. It travels in the blood to muscles and bones, where it causes cells to divide and grow. A person who does not produce enough of this hormone is much shorter than normal, often less than 1.2m in height. Unfortunately, growth hormone taken form other animals does not work in humans. So the only way doctors could obtain hormone to treat their patients was by extracting it from the pituitary gland of dead people. Since each gland only contains a minute amount, this process was very time consuming and extremely expensive. It took 650 glands to produce just 2 or 3 grams of the hormone. At one time, human growth hormone was much more expensive than gold gram for gram. Now by GE it could cheaply produced and the cost of treatment has fallen dramatically.