Cancer Vaccines are vaccines that treat either existing cancer or prevents any development of cancer. The vaccines that prevent an infection that causes cancer are Preventive cancer vaccines. Some of the preventive vaccines available include the HPV and hepatitis B vaccines which prevents cervical, anal, and head and neck cancers. On the other hand the vaccines that trigger the immune system to recognize and destroy certain markers, or antigens, present on or in cancer cells are termed as Therapeutic cancer vaccines.