Cancer vaccine, in a broad sense, can not only prevent people from getting cancer but also treat cancer.
Why this therapy can work? The reason why people get some specific cancers including liver cancer, cervical cancer is that the normal cells get infected by virus and these cells produce cancerous phenomenon. The traditional vaccines can prevent people from the infection of viruses,such as hepatitis B vaccine , cervical cancer vaccine and rabies vaccine.
Some scientist believes that cancer cells exist in human body and most of cancer cells can be eliminated by immune system. So scientists are researching a new kinds of vaccine to fight the cancer cells which has existed in people. When the immune system breaks down, cancer cells appear. The traditional treatments of cancer are operation, chemotherapy and radiation therapy, but chemotherapy and radiation therapy kill both cancer cells and normal cells. So the cancer vaccine aims to cure cancers and minimize the side effects.
How the immunity works, when takes cancer vaccine? A special protein ( antigen ) is spread on the cancer cells and the antigen can stimulate the immunity to fight the cancer cells. Different cancer cells have different antigens. Some of antigens even do not present on normal cells. When natural killer cells and dendritic cells of immunity detect these special antigens, they will start eliminating these cancer cells and even can promote cytotoxin T lymphocyte kills cancer cells.
How the vaccine works? The normal immunity can attack the cancer cells which present special antigen protein on cover. If the immune action on special antigens of cancer cells
is produced, the cancer cells can be attacked and killed. The theory of cancer vaccine is to use vaccine to stimulate endritic cells of immune system. After the appearance of tumor antigen, dendritic cell can promote produce cytotoxin T lymphocyte to eliminate the specific cancer cells. The vaccine can also contribute to stimulating secretion of cytokines of Helper T cells, which strengthens the ATK of Cytotoxin T lymphocyte.
If there are still a few cancer cells in human body after the operation,chemotherapy or radiation therapy, it may lead to cancer recurrence and metastasis. Because cancer vaccine can stimulate cytotoxin T lymphocyte attacks specific cancer cells and detect them in human body, the vaccine can prevent the cancer recurrence and metastasis.