Reporting by Julie Steenhuysen; Editing by Xavier Briand) at

The U.S. introduction of a vaccine to prevent cervical cancer in 2006 has reduced infections with the human papillomavirus or HPV – the sexually transmitted virus that causes the disease – by more than half among girls and young women, U.S. health officials said on Wednesday.

The results were better than expected and may even suggest that unvaccinated individuals are benefiting because of a drop in the number of infections circulating, the team reported in the Journal of Infectious Diseases.

“This report shows that HPV works well, and the report should be a wake-up call to our nation to protect the next generation by increasing HPV vaccination rates,” Dr Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention, said in a statement.

Frieden said only a third of U.S. girls aged 13-17 have been fully vaccinated with HPV vaccines, which include Merck’s Gardasil and GlaxoSmithKline’s Cervarix.

That compares with far higher vaccination rates in other countries such as Rwanda, where more than 80 percent of teenage girls have been vaccinated.

“Our low vaccination rates represent 50,000 preventable tragedies – 50,000 girls alive today will develop cervical cancer over their lifetime that would have been prevented if we reach 80 percent vaccination rates,” Frieden said.

In the study, a team led by the CDC’s Dr. Lauri Markowitz used data from a large health survey to compare rates of infection with certain strains of the HPV virus among girls and women aged 14-19 in the four-year period before the introduction of the vaccine (2003-2006) and after its introduction (2007-2010).

The study largely reflects the impact of Merck’s Gardasil. In 2006 it became the first HPV vaccine to win U.S. approval.