New vaccines appear effective against genital, cervical diseases

Washington -- Two separate studies show that two companies have developed human papilloma virus (HPV) vaccines that appear to be highly effective in preventing vaginal cancer, vulvar cancer and genital warts.

The recently completed, separate studies involved a vaccine called Gardasil, developed by Merck, and one developed by GlaxoSmithKline. Earlier studies have shown that Gardasil also protects against cervical intraepithelial neoplasia (CIN), precancerous lesions that develop into cervical cancer.

Both studies’ results were presented at the American Society for Microbiology’s Interscience Conference on Antimicrobial Agents and Chemotherapy, held here recently.

In the Merck-sponsored Gladasil study, 2,261 sexually active women ages 16 to 23 were inoculated with Gardasil and received additional vaccinations at one and six months. A similar group of 2,279 women received placebo on the same schedule. None of the former group developed genital warts, high-grade vulvar epithelial intraepithelial neoplasia (VIN) or vaginal intraepithelial neoplasia (VaIN), while 40 cases of genital warts or precancerous lesions occurred among women in the latter group.

In the other study, GSK researchers say they found that inoculating females 10 to 14 years old with GSK’s HPV vaccine resulted in seroconversion, or the production of antibody titers, that were nearly double those of females 15 to 25 years old. The researchers say this is critical because HPV infection usually occurs within a year of women becoming sexually active.

The GlaxoSmithKline vaccine differs from the Merck vaccine in that the GSK version targets only two HPV strains and is aimed only at preventing cervical cancer. The Merck vaccine targets four strains, aiming at not only cervical cancer but external genital lesions such as genital warts. Based on earlier success in studies involving cervical cancer, Merck filed for approval of Gardasil in early December.

There are more than 100 strains of human papilloma virus, and each year nearly 500,000 cases of cervical cancer are diagnosed worldwide. Annually, cervical cancer is fatal to nearly 300,000 women worldwide.