You’re probably familiar with traditional vaccines for diphtheria, mumps, whooping cough, polio, rubella, tetanus, tuberculosis, and other diseases that have been nearly eliminated in the United States because so many people have been vaccinated. For these diseases, a killed or weakened version of the organism that causes the disease is given to a healthy person to rev up the immune system and start a response.
There are some cancers that have been linked to viruses. Some strains of the human papilloma virus (HPV), which causes genital warts, have been linked to cervical, anal, throat, and other cancers. HPV vaccines may help protect against some of these cancers. People with long-term hepatitis B infections have a higher risk of liver cancer. So, the hepatitis B vaccine may reduce the risk of liver cancer.
Still, much of the research on vaccines for cancer are on cancer treatment vaccines. Treatment vaccines try to get the immune system to attack cancer cells. Treatment vaccines are different because they don’t prevent disease, they work to stimulate the immune system to kill a disease that is already there. You don’t receive a cancer treatment vaccine until after you’ve been diagnosed.
Cancer treatment vaccines are made up of cancer cells, parts of cells, or antigens, the proteins on a foreign cell -- like a cancer cell -- that allow the immune system to recognize it as “other.” In some cases, a person’s immune cells are taken from the body and exposed to these substances in the lab to create the vaccine. Once the vaccine is ready, it’s put back into the body to boost the immune system’s response to cancer cells.
Cancer treatment vaccines may take months to produce a noticeable immune system response, so they may be most useful to reduce the risk of the cancer coming back (recurrence) after the main cancer treatments, such as surgery, are done. Doctors call treatments given after surgery “adjuvant” treatments.
Right now, no cancer treatment vaccines have been approved by the U.S. Food and Drug Administration to treat breast cancer. Still, there are several clinical trials looking at breast cancer treatment vaccines.
Some of the studies are looking at treatment vaccines in combination with other treatments, such as Herceptin (chemical name: trastuzumab) or chemotherapy.