Cervical cancer vaccines: emerging concepts and developments

Certain human cancers are linked to infection by oncogenic viruses that are able to cause transformation of the normal host cell into a cancerous cell. Human papillomavirus (HPV) DNA and expression of viral transforming proteins are found in virtually all cervical cancer cells, indicating an important role of this virus in the pathogenesis of the disease. Evidence exists that the immune response to cancer cells can play a major role in determining the outcome of disease. The fact that HPV is a necessary cause for cervical cancer provides a clear opportunity to develop a therapeutic vaccine against the virus to treat patients with cervical cancer at its early and late stages. Development of a prophylactic vaccine for HPV would also reduce the incidence of cervical neoplasias by preventing virus infection. Various candidate HPV vaccines are being developed and tested in animal models and/or in human clinical trials. These HPV vaccines, both preventive and therapeutic, are the subjects of this review.