Vaccinations for Cancer

For the past several decades, countless studies of been conducted in hopes to finding a vaccine that will allow our immune system to recognize carcinogenic cells and destroy them. Though the FDA still not yet approved most of them them, numerous clinical trials are currently in progress. As of now there are two main types of cancer vaccinations. The first type is Preventative vaccines which are intended for health individuals with no cancer and the second type are Treatment vaccines intended for individuals with already existing cancer. These sets of vaccination belong to a class of medication called Biological Response Modifiers where the ultimate goal is to stimulate and restore the body’s ability to fight off infections. At first researchers thought that similar to other vaccinations like Measles and Mumps, the vaccination would allow the immune system to recognize specific cancerous cell thus preventing infection, but because carcinogenic cells mutate so rapidly it is impossible to create a good response vaccine. This is where Preventative vaccinations come into play. Instead of targeting cancerous cells, these vaccinations target viruses, bacterium, and parasites that lead to cancer.

As of now, the U.S. Food and Drug Administration has only approved two preventative vaccinations Gardasil and Cervarix, these two vaccines are used to prevent two types of Human Papillomavirus (HPV) which causes about 70% of all cervical cancer cases worldwide. Protecting against HPV may also prevent vulvar, vaginal, anal, and oropharyngeal cancers. Other types of targeted organisms include Hepatitis virus B & C which can cause various types of liver cancers, helicobacter pylori a bacterium that causes stomach cancer and parasites such as schistosomes which causes bladder cancer. Visit site

http: //www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines to see full list.

Lastly, there are the treatment vaccines used to treat patients that are already diagnosed with cancer. These are sometimes called True Cancer Vaccines and are only specific from person to person. They are meant to trigger a person’s own specific response in which the body will then attack cells with one or more specific antigens. The goal of these vaccines is to delay or stop cancer cell growth causing the tumor itself to shrink and prevent the cancer from coming back into the system. Last year, FDA has approved the first cancer treatment vaccine called Provenge. This vaccine is made for men with metastatic prostate cancer and is designed to stimulate an immune response to prostatic acid phosphatase (PAP) which is an antigen found in prostate cancer cells. Since this treatment is specific from patient to patient, how the vaccination process works is first white blood cells are extracted from the patient and exposed to PAP. Then, the white blood cells are infused back to the patient via vein. This process is repeated two more times, two weeks apart. The goal is to stimulate an immune response to recognize the PAP antigen. So far, this clinical trial shows good response.

Sources:

http://www.cancer.org/Treatment/TreatmentsandSideEffects/TreatmentTypes/Immunotherapy/immunotherapy-cancer-vaccines

http://www.cancer.gov/cancertopics/factsheet/Therapy/cancer-vaccines

Murphy KM, Travers P, Walport M, editors. Janeway's Immunobiology. 7th ed. New York: Garland Science, 2007