CDC finds vaccines halved HPV infections in teenage girls

In the furor over human papillomavirus (HPV) vaccines in the U.S., whether they work has taken a backseat to sociopolitical concerns. Australia has reported positive results from its HPV shots campaign though, and now the U.S. has its own data to show the effectiveness of the vaccines.

A study published in the Journal of Infectious Diseases found that incidence of HPV infections by the strains included in Merck's ($MRK) Gardasil and GlaxoSmithKline's ($GSK) Cervarix fell by 56% among 14- to 19-year-olds in the vaccine era. The decline is greater than anticipated, possibly because of the herd immunity effect. Centers for Disease Control and Prevention (CDC) officials see the result as compelling evidence that more people should receive the vaccine. The backlash against HPV vaccines means immunization rates in the U.S. are lower than in Rwanda, and this has implications for public health. 

"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% vaccination rates. For every year we delay in doing so, another 4,400 girls will develop cervical cancer in their lifetimes," CDC Director Dr. Tom Frieden said. CDC data shows that in the U.S. there are 27,000 cases of HPV-related cancer each year. More than two-thirds of these cases affect women--with cervical cancer a particular threat--but men are at risk too. For men, throat cancer is the most common form, a fact film star Michael Douglas highlighted recently when discussing his own experience with the disease.

The challenge for vaccinemakers and public health officials is to use the renewed discussion of HPV and evidence of the shots' efficacy to win over a skeptical public. A 2010 survey of parents found that 44% had no intention of giving their children the HPV vaccine. If the U.S. is to increase its HPV vaccination rate up above 80%, it must show these parents that benefits outweigh the risks.

- here's the journal abstract
- get the CDC's take
- read more in NPR's post