In an article last year, we said it was still too soon to tell whether Gardasil, a vaccine that protects against 4 common strains of HPV (human papillomavirus), would make a difference in HPV rates on a large scale. Just a year later, a new study has shown that among 14- to 19-year-old women, rates of the HPV strains the vaccine protects against have gone down. Way down.
In late 2006, the Centers for Disease Control and Prevention (CDC) recommended that all females ages 11-12 be vaccinated against HPV, with catch-up vaccines for those ages 13-26. The vaccine is given as three shots within the span of a year. The new study, conducted by the CDC, looks at the types of HPV that women in the U.S. had in 2003-2006 versus 2007-2010—before versus after the HPV vaccine, in other words.
If the vaccine is working, there should be fewer young women with HPV strains 16, 18, 11, and 6 (the ones the vaccine protects against) and no changes in terms of other strains of HPV (there are more than 40 types of HPV in total!). And that's exactly what the study found.
Among young women ages 14-19, there was an overall decrease of 56% in the four HPV strains the vaccine protects against—even though only 34% of those women actually got at least one dose of the vaccine. There was no change in the number of young women who had other strains of HPV.
Among older women (none of whom would have gotten the vaccine), there were no changes in the rate of HPV. What about those who were in the 13-26 age range when the CDC made their recommendation? Only 18% of 20- to 24-year-old women in the study got at least one dose of the vaccine and only 9% got all three doses—too few to show an overall change in the rate of HPV infection in that group.
What does it all mean?
The exciting news: The HPV vaccine works and the women who have been protected by it are less likely to have to deal with genital warts or cervical cancer later in their lives.
The crap news: In the U.S., so few women are getting vaccinated. Only 34% of the 14- to 19-year-old women in the study had gotten at least one dose of the vaccine, and even fewer (21%) had all three doses. In a press release about the new study, Dr. Tom Frieden, Director of CDC, estimates that the U.S.'s "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." Why does Dr. Frieden suggest an 80% vaccination rate? That's the HPV vaccination rate in Rwanda, the first low-income country in the world to provide universal access to the HPV vaccine.
We hope that the good news about the HPV vaccine and the strong proof that it's safe will result in more people getting the shots. The HPV vaccine is now recommended for folks up to age 26, including guys, and the study also suggests that even one dose out of three can make a difference, though of course doing the full three doses is the best option. This is cause for celebration and, if you're under 27 and haven't been vaccinated, a visit to your health care provider!