開幕典禮及大會特別演講

P-2
Perspectives in the Preventive and Therapeutic HPV Vaccines for Cervical Cancer
T.-C. Wu1,2,3,4
Departments of Pathology1,Oncology2, Obstetrics and Gynecology3, and Molecular Microbiology and Immunology4, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA

  Cervical cancer continues to be a major global health care problem and remains the second leading cause of cancer death in women worldwide. A clear understanding of human papillomavirus (HPV) as a necessary cause and the pathogenesis of cervical cancer has created an opportunity to control cervical cancer through vaccination against HPV. The licensed HPV preventive vaccines targeting the HPV major capsid protein, L1 represent a triumph for HPV vaccine development. While these preventive HPV vaccines have proven to be highly effective in protecting against cervical disease relating to the HPV types included in the vaccine, they have partial or no efficacy against other HPV types. Furthermore, because these vaccines contain only two oncogenic HPV types, HPV-16 and 18, which account for approximately 75% of cervical cancers, they do not provide protection against all cervical cancers. In addition, since ~80% of cervical cancer deaths occur in developing countries that lack the resources and infrastructure for cytologic screening and intervention, an ideal preventive vaccine should provide broad protection against most high-risk HPV types as well as be cost-efficient in order to be made available in low-resource areas to maximize the impact of vaccination on the global cervical cancer burden. Currently, significant efforts have been made in the development of a cost-effective, pan-preventive vaccine targeting the HPV minor capsid protein, L2. Another significant obstacle for the elimination of cervical cancer is the high prevalence of established HPV infections and HPV-associated disease. The existing preventive HPV vaccines are not effective in controlling pre-existing HPV infection. This is a serious concern since there is currently a considerable burden of HPV infections worldwide. It is estimated that it would take approximately 20-30 years from the implementation of mass vaccination for highly effective preventive vaccines to impact the cervical cancer rates due to the prevalence of a significant population with existing HPV infections and slow process of carcinogenesis. Thus, in order to accelerate the control of cervical cancer and to treat currently infected patients, it is important to develop therapeutic vaccines against HPV. Various forms of therapeutic vaccines targeting HPV oncogenic proteins E6 and E7 antigens are currently being developed in preclinical models. Because HPV oncogenic proteins E6 and E7 are constantly expressed in the majority of HPV-associated malignancies and they are responsible for the malignant transformation and progression of HPV-associated cervical cancer, they represent ideal targets for the development of therapeutic HPV vaccines. The encouraging results from some of these preclinical studies have led to their translation to clinical trials.