A new vaccine aimed at preventing cervical cancer is nearly 100 percent effective against the two types of the human papillomavirus (HPV) responsible for most cases of cervical cancerstrains 16 and 18. Results of an international meta-analysis study of the vaccine are published in the June 1 issue of the journal Lancet.
In the current and largest study to date, researchers combined and analyzed the data from four randomized trials that involved 20,583 women ages 15 to 26 from more than two dozen countries across Europe, North America, Latin America and Asia. Participants were randomly assigned to receive the HPV vaccine or placebo and followed for an average of three years.
Researchers found that the prophylactic administration of the vaccine was highly effective in preventing pre-malignant changes of the cervix, also known as cervical dysplasia.
"This is a much larger combined study that shows 99 percent efficacy, a clear reduction of pre-cancerous cervical lesions. We demonstrated significant protection against serious HPV-related diseases, including high-grade cervical pre-cancers, in women not previously exposed to the relevant HPV types targeted by the vaccine," says Kevin Ault, MD, associate professor of obstetrics and gynecology at Emory University School of Medicine, one of the authors of the study and a key researcher in the development of the vaccine.
HPV strains 16 and 18 are responsible for about 70 percent of all cases of cervical cancer. In clinical trials the vaccine, manufactured by Merck under the name Gardasil, also demonstrated a high efficacy rate in protection from HPV types 6 and 11, which together cause about 90 percent of all cases of genital warts. All four types cause a large number of abnormal Pap test results and low-grade cervical lesions.
Cervical cancer is the second most common cause of cancer deaths in women worldwide, accounting for about 240,000 deaths each year. In 2007 expe
Contact: Juliette Merchant