Human papillomavirus immunology and vaccine prospects.

As a result of several recent advances in molecular biology, the association between human papillomavirus (HPV) infection and cervical cancer has been firmly established and the oncogenic potential of certain HPV types has been clearly demonstrated. These observations provide the impetus for the development of novel vaccines to prevent or treat HPV-associated cervical cancer. Because there is no effective culturing system to propagate HPV, traditional approaches for studying HPV and developing vaccines have been hampered. However, recent studies using recombinant subunit preparations in animals have yielded promising results and encourage their investigation in human trials. Strategies currently under investigation focus on the induction of effective humoral immune responses for prophylaxis against subsequent HPV infection; for the treatment of existing HPV infections, techniques to improve cell-mediated immunity by enhancing viral antigen recognition are being studied. Small-scale human trials using several different vaccine approaches should be completed within the next few years and field trials of the most promising one(s) could begin within a decade. The development of successful therapeutic and/or prophylactic vaccines offers an attractive alternative to existing screening and treatment programs for cervical cancer and may result in a substantial reduction in the worldwide morbidity from this disease.