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.
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
Because cancer affects almost everyone somehow (like the whole Steve Jobs fiasco), I think that this post was particularly interesting. While I had an idea of these vaccines, I didn't know the details of Provenge. It is very interesting how the white cells are taken out and then put back into the patient to stimulate the immune system. I think it gives a great sense of hope and confirmation that our efforts are helping push forward the idea of a cure for cancer.
ReplyDeleteI recently heard a fascinating story discussing a new way to target tumors. This would be more along the lines of a treatment vaccine in that it would be used in those who already diagnosed with cancer but instead of triggering the body’s own response, it would bring in a virus to do the job. So far they have successfully developed a method to intravenously give a patient a virus able to specifically infect tumors, a huge achievement in itself. They are now continuing studies in hopes of seeing benefits of infecting these cells. As mentioned, this sort of treatment would contribute greatly to medicine and society as a whole.
ReplyDeleteI definitely recommend listening to the story:
http://www.npr.org/2011/09/02/140146786/delivering-viruses-to-try-and-kill-tumors
I found a very interesting website that answers frequently asked questions about HPV vaccinations. It's fascinating that only HPV strains 16 and 18 are protected by the vaccines. I wonder how many strains of HPV exist, and what makes one strain more dangerous than another? Maybe in the future a vaccine will be created that is effective on all strains of HPV.
ReplyDeletehttp://www.cancer.gov/cancertopics/factsheet/prevention/HPV-vaccine