Studies Support Cervical Cancer Vaccine's Effectiveness in Young Girls

And another trial pinpoints HPV as prime cause of throat cancer.

By E.J. Mundell
HealthDay Reporter
Wednesday, May 9, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

WEDNESDAY, May 9 (HealthDay News) -- Expanded findings from trials that led to U.S. approval of the cervical cancer vaccine Gardasil find it extremely effective in preventing precancerous lesions of the cervix.

The vaccine prevents infection with four strains of the sexually transmitted human papilloma virus (HPV), the leading cause of cervical cancer.

In two studies involving nearly 18,000 girls and women, Gardasil proved almost 100 percent effective in preventing precancerous cervical lesions linked to those strains.

The new studies also found that Gardasil is much more effective when given to girls or women before they become sexually active -- bolstering current recommendations from the U.S. Centers for Disease Control and Prevention that 11- and 12-year-old girls should routinely receive the vaccine as part of school vaccination efforts.

Moves by states to mandate vaccination of young girls have met with strong opposition from conservatives and some parents. But doctors say the new findings, reported in the May 10 issue of the New England Journal of Medicine, support those state mandates.

"All vaccines are going to work best before you have the disease," explained Dr. Kevin Ault, a co-researcher on one of the trials and an associate professor of gynecology and obstetrics at Emory University in Atlanta.

"There's lots of good, practical reasons to give the vaccine to 11-year-olds," he said, including the fact that they have strong immune systems and are already getting shots against other infectious diseases. "But that's one of the best reasons: that they are unlikely to have gotten the virus at that point," Ault added.

Another study, published in the same issue of the journal, points to a potential new reason for both women and men to worry about HPV: throat cancer. U.S. researchers say the virus -- most likely transmitted through oral sex in this case -- is probably the number one cause of throat malignancies, which affect about 11,000 Americans each year.

HPV's connection to cervical cancer remains the biggest concern, however, since it is the second biggest cause of cancer death among females worldwide, killing an estimated 240,000 women each year. The CDC now estimates that more than 20 million U.S. men and women carry cervical cancer-linked HPV.