HPV vaccine shown to "substantially" reduce cervical cancer.

2004 DEC 2 - (NewsRx.com & NewsRx.net) -- An international clinical trial has shown extremely promising results for a vaccine against the most common causes of cervical cancer.

Diane Harper of the Norris Cotton Cancer Center at Dartmouth-Hitchcock Medical Center (DHMC) and Dartmouth Medical School, who led the study, and her fellow authors said the vaccine has the potential to greatly reduce deaths from cervical cancer, one of the leading causes of cancer mortality among women worldwide.

The vaccine is targeted to immunize against two different types of high-risk human papillomavirus (HPV-16 and HPV-18) that cause an estimated 70% of cervical cancer cases.

HPV is a commonly occurring infection, transmitted by skin to skin contact, most commonly through normal sexual interactions. Although most cases of HPV resolve themselves through natural immunity, a percentage of cases will progress to cervical cancer.

Currently, an estimated 280,000 women die from cervical cancer each year, most of them in the developing world. Of the 500,000 cases of cervical cancer diagnosed annually, 70% are attributed to infection from HPV-16 and 18. The 5-year prevalence of cervical cancer worldwide, i.e., the number of women in any 5-year period of time with cervical cancer, is 1.4 million.

In the blinded, randomized trial of 1,113 women from throughout the U.S., Canada, and Brazil, participants received three doses of the experimental vaccine or a placebo over 6 months.

At 27 months of follow-up, the vaccine showed an extremely high rate of efficacy, the authors reported in the November 13, 2004, issue of The Lancet. In those women who completed the protocol - receiving all three shots and participating in all scheduled testing and follow-up - the vaccine was 100% effective against persistent HPV16/18 infections.