How Vaccines work for Cancer

Most vaccines are for prevention, not for treating established disease. It is fairly easy to stimulate antibodies and other specific immunity against a foreign germ which may attack in the future. Cancer, however, involves “self” cells which have turned rogue, and the immune system has instructions to leave “self” cells alone. Without this protection, autoimmune diseases would be much more common. So, how do we stimulate the immune system to attack tumor cells?

One way is to remove tumor cells, kill them with radiation, and mix them with immune-stimulant chemicals. This mixture is then injected back into the body in the hopes that it will now be seen as foreign. As expected, this approach is complex, costly, and has limited effectiveness. Several other vaccine strategies have been tried, but Dendritic Cells (DC), hold tremendous potential as they can directly stimulate killer T cells without any assistance. We can grow millions of DC from a unit of whole blood, and each DC can activate up to 3,000 killer cells. Most tumor immunologists agree that a ratio of killer cells to tumor cells of at least 10: 1 is required for a complete response to vaccine treatment. To accomplish this, we must first remove at least half of the cancer cells in the body prior to the vaccine treatment. Unfortunately, radiation, surgery, and chemotherapy all degrade the killer cells, so another method must be used.