[Cervical cancer prevention: the impact of HPV vaccination].
Cervical cancer remains a critical public health problem that is second only to breast cancer in overall disease burden for women throughout the world. In spite of the success of cervical cancer screening, Pap cytology screening is yet to be effectively implemented or has failed to reduce cervical cancer rates to an appreciable extent. Screening appears to benefit only a small fraction of women although a much larger percentage endures the inconvenience of the Pap test in order to avoid cervical cancer. The establishment of Human Papillomavirus (HPV) infection as the necessary cause of cervical precancers and cancers provides a tremendous opportunity for cervical cancer prevention through vaccination. HPV 16 and 18 which cause 70% of cervical cancers worldwide. Thus a prophylactic vaccine to prevent HPV related precancerous lesions and cancers would save lives, reduce the need for costly medical procedures and provide both women and communities throughout the world with substantial benefits. Based on the induction of neutralizing antibodies by non infectious Virus Like Particles (VLP) of L1 capside protein, prophylactic HPV vaccines have consistently induced high titter of neutralizing antibodies with minimal side effects and induce more than 90% protection from persistent HPV 16-18 infection and HPV 16 and 18 associated high-grade Cervical Intraepithelial Neoplasia (CIN) in proof of concept efficacy trials. HPV 16-18 vaccination will prevent HPV16-18 incident infection, and subsequently decrease in 90% the frequency of abnormal Pap attributable to these types and in about 50% overall abnormal Pap. HPV vaccination will reduce the number of women who require colposcopy, biopsy and cervical treatment for precancerous cervical lesions. The level of protection from death due to cervical cancer could exceed 95%. Three large phases prophylactic HPV VLP trials are now in progress and will form the basis for licensing of candidate vaccines in 2006. HPV vaccination targeting young female adolescents, aged 11 to 16 years, with a catch-up of those aged 17-25 years, would be a strategy to be addressed. Cervical cancer screening strategies, that will be cost-effective for the proper surveillance of women protected by HPV vaccination, are under analysis.