When most people think of vaccines, they think of those that help to prevent illness. There is, however, another type of vaccine. A person may also receive a therapeutic vaccine, which is given after a person has already contracted an illness. In such a case, the vaccine is typically used to lessen the severity of or treat a condition that has already developed. Therapeutic vaccines are used less often than preventative vaccines because scientists are still studying them.
Preventative vaccines work in a predictable manner. They are usually created to prevent a particular type of infection. In such a case, the agents used to make the vaccine help provoke the response of the patient’s immune system enough to create antibodies against the infection. As a result, the patient is less likely to contract the infection if the body is exposed to it at a later date. This differs from the use of a therapeutic vaccine, which does not prevent the infection at all; instead, it works to treat the infection or reduce the patient's suffering.
One type of therapeutic vaccine, called sipuleucel T, is designed for use in patients who have prostate cancer. It is intended to help people who have already been diagnosed with this type of cancer. When this prostate cancer vaccine is administered, it is supposed to boost the immune system so it can fight the cancer cells that have already developed. This therapeutic vaccine cannot stop prostate cancer from developing, however.
One of the factors involved in the production of therapeutic vaccines is the manner in which the immune system responds to some types of invaders. In some cases, the immune system’s response is too weak, and sometimes it doesn’t seem to recognize an invasion at all. Therapeutic vaccines may help to stimulate the immune system to fight the invader or destroy cancerous cells.
The development of therapeutic vaccines is in its early stages in comparison to the development of vaccines that prevent illness. To understand this type of vaccine better, scientists conduct experiments to evaluate the feasibility of creating therapeutic vaccines to treat various types of illnesses. For example, some researchers spend time working on the development of therapeutic vaccines for human immunodeficiency virus (HIV), herpes, and other types of cancer. Some research studies have produced promising results, and the use of therapeutic vaccines may someday become as common as the administering of preventative vaccines.