Vaccines against human papillomavirus and perspectives for the prevention and control of cervical cancer

Résumé 0

Today, “persistent” infections by certain types of humanpapillomavirus (HPV) are considered necessary for developingcervical cancer. Producing efficient vaccines against these virusesmay eventually lead to a great reduction in incidence andmortality rates of this cancer. In the case of HPV, the productionof traditional vaccines usually based in dead or attenuatedviruses is not possible due in part to the lack of systems wherelarge quantities of viral particles could be obtained. Fortunately,the expression of the late L1 protein alone, or in combinationwith L2, leads to the generation of structures resembling truevirions that have been called virus-like particles (VLPs) andconstitute excellent candidates as prophylactic vaccines. VLPshave shown to be very immunogenic, and have preventeddevelopment of natural or challenged infections in both animalsystems and humans. Recently, HPV16 VLPs were shown to bevery efficient to prevent the development of “persistent”infections, as determined by PCR assays, in a large group ofvaccinated women. Therapeutic vaccines, on the other hand,are expected to have an impact on advanced lesions and residualillness, by taking advantaje of the fact that early E6 and E7genes are thought to be constitutively expressed in cervicaltumors and precursor lesions. Finally, DNA-based vaccines couldrepresent a useful alternative for preventing infections by genitalHPV. This paper is available too at: http://www.insp.mx/salud/index.html