IT IS A NON-INFECTIOUS RECOMBINANT, QUADRIVALENT VACCINE PREPARED FROM THE HIGHLY PURIFIED VIRUS-LIKE PARTICLES (VLPS) OF THE MAJOR CAPSID (L1) PROTEIN OF HPV TYPES 6, 11, 16, AND 18. PV ONLY INFECTS HUMANS. THE EFFICACY OF L1 VLP VACCINES IS MEDIATED BY THE DEVELOPMENT OF HUMORAL IMMUNE RESPONSES.
HUMAN PAPILLOMAVIRUS (HPV) CAUSES SQUAMOUS CELL CERVICAL CANCER (AND ITS HISTOLOGIC PRECURSOR LESIONS CERVICAL INTRAEPITHELIAL NEOPLASIA [CIN] 1 OR LOW GRADE DYSPLASIA AND CIN 2/3 OR MODERATE TO HIGH GRADE DYSPLASIA) AND CERVICAL ADENOCARCINOMA (AND ITS PRECURSOR LESION ADENOCARCINOMA IN SITU [AIS]). HPV ALSO CAUSES APPROXIMATELY 35-50% OF VULVAR AND VAGINAL CANCERS. VULVAR INTRAEPITHELIAL NEOPLASIA (VIN) GRADE 2/3 AND VAGINAL INTRAEPITHELIAL NEOPLASIA (VAIN) GRADE 2/3 ARE IMMEDIATE PRECURSORS TO THESE CANCERS.
CERVICAL CANCER PREVENTION FOCUSES ON ROUTINE SCREENING AND EARLY INTERVENTION. THIS STRATEGY HAS REDUCED CERVICAL CANCER RATES BY APPROXIMATELY 75% IN COMPLIANT INDIVIDUALS BY MONITORING AND REMOVING PREMALIGNANT DYSPLASTIC LESIONS.
HPV ALSO CAUSES GENITAL WARTS (CONDYLOMA ACUMINATA) WHICH ARE GROWTHS OF THE CERVICOVAGINAL, VULVAR, AND THE EXTERNAL GENITALIA THAT RARELY PROGRESS TO CANCER. HPV 6, 11, 16, AND 18 ARE COMMON HPV TYPES.