Are there vaccines under development to prevent cancer?
Yes, some vaccines currently under investigation have the potential to reduce the risk of cancer. These vaccines target infectious agents that cause cancer and are similar to traditional prophylactic vaccines, which target other disease-causing infectious agents such as those that cause polio or measles. Non-infectious components of cancer-causing viruses, commonly the viral coat proteins (proteins on the outside of the virus), serve as antigens for these vaccines. It is hoped that these antigens will stimulate the immune system in the future to attack cancer-causing viruses, which should, in turn, reduce the risk of the associated cancer. For example, the human papilloma virus (HPV) causes nearly all cases of cervical cancer. Preventing infection by HPV is expected to dramatically reduce the risk of cervical cancer. One promising vaccine against HPV is expected to enter large-scale human trials in the near future. Another promising prevention vaccine targets the hepatitis C virus, lin
