Papillomavirus infection is more common in youngsexually active people. It is so prevalent that from 75% to 80% of this populationwill be infected in their lifetime. Most lesions will be eradicated spontaneouslyat the point of not being detected even with the most sensible methods. Persistentinfections with oncogenic HPV increase intraepithelial neoplasia and cancerrisks. Two ways of prevention may be proposed: screening for precursor lesionsand immunization against HPV, to avoid them. Although anogenital cancer incidenceis decreasing with screening methods, costs are high and emotional disturbancemay be caused by an abnormal result. So, vaccines to prevent diseases associatedto HPV must be available. In the last decade, clinical tests began with severalvaccines targeting the most frequent HPV types. The goal of prophylactic vaccinesis to prevent primary or persistent HPV infections, and thus prevent cervicalcancer and/or genital warts and the aim of the therapeutic types is to preventprogression of HPV infection, induce regression of intraepithelial neoplasiaor condylomata, or eradicate residual cervical cancer. Prophylactic HPV vaccinesin late stages of clinical testing are composed of HPV L1 capsid protein thatself-assemble into virus-like particles (VLPs) when expressed in recombinantsystems, resulting in strong adaptive immune responses that are capable of neutralizingsubsequent natural infections. Some studies observed 100% efficacy in preventingclinical disease for specific HPV types at least 5 years after immunization.Vaccines that target E6 and E7 proteins also represent an important strategyto control HPV-associated lesions and are in test in animal models. HPV vaccinesseem to be more effective when administered prior to initiation of sexual activity,and vaccination campaigns should target preadolescent and adolescent populations.It is expected that with good coverage of the vaccine, 70% of cervical cancerswill be prevented like other anogenital diseases caused by HPV infection.
