A Second HPV Vaccine May Also Prevent Cervical Cancer

Recent reports have shown that a quadrivalent human papillomavirus (HPV) vaccine, approved by the FDA last year, prevents precancerous cervical and anogenital lesions (Journal Watch May 9 2007). Of the four HPV strains in this vaccine, only two — HPV 16 and 18 — are oncogenic. A second, competing vaccine directed against only these two HPV types was previously shown to be immunogenic and to prevent cervical HPV 16 and 18 infection.

To test whether the vaccine prevents precancerous lesions, manufacturer-supported researchers randomized 18,644 healthy women, aged 15 to 25, to receive three doses of the bivalent vaccine or a control hepatitis A vaccine at 0, 1, and 6 months. All women had periodic Pap smears (plus colposcopy and biopsy as indic…