In the pipeline: preventive vaccine against breast cancer

Could this be the vaccine we have been waiting for? Researchers at Cleveland Clinic announced last week that we may be closer to having a vaccine to fight breast cancer that previously thought. The researchers have developed a vaccine that was tested and shown to be effective in mice. The next step is to test the vaccine in clinical trials, e.g. in humans.

According to Vincent Tuohy, Ph.D., the study’s principal investigator and an immunologist in Cleveland Clinic’s Lerner Research Institute Department of Immunology:

“We believe that this vaccine will someday be used to prevent breast cancer in adult women in the same way that vaccines prevent polio and measles in children. If it works in humans the way it works in mice, this will be monumental. We could eliminate breast cancer.”

There are two main types of vaccines: preventive vaccines and therapeutic vaccines. Preventive vaccines are those that we are most familiar with – the childhood inoculations such as MMR and DPT, as well as adult vaccines against yellow fellow and hepatitis. These vaccines start up the immune system to produce that antibodies for certain antigens, thus protecting the recipient from certain diseases. Therapeutic vaccines (also called treatment vaccines), on the other hand, are the new kid in the block. They work not a preventive measure but as treatment of an already existing condition.  The vaccine is designed to boost the immune system to better fight or control an ongoing infection or disease. Currently, there are many therapeutic vaccines against cancer being developed and tested.

There are currently two preventive vaccines targeting some types of cancer. According to the US-based National Cancer Institute:

“The U.S. Food and Drug Administration (FDA) has approved two types of cancer preventive vaccines: A vaccine against the hepatitis B virus, which can cause liver cancer in chronically infected people, and a vaccine against human papillomavirus types 16 and 18, which are responsible for about 70 percent of all cases of cervical cancer.”

The Cleveland Clinic prototype is the first of its kind preventive vaccine for breast cancer. The vaccine is made from the antigen and has been shown to prevent the development of breast cancer tumors in mice as well as slow down the growth of existing tumors. The mice tested were genetically engineered to be prone to breast cancer, thus representing a high-risk population. All these mice did not develop breast cancer. The α-lactalbumin antigen targets breast cancer cell without damaging healthy breast tissue. The vaccine will be tested in women as early as next year, targeting women over 40 years old, the age where breast cancer risk starts to increase and the likelihood of pregnancy is low.