That makes this vaccine completely different from the 14 others on the CDC's recommended schedule, save perhaps Hepatitis B, which is primarily (but not exclusively) transferred via intravenous drug use and sexual contact.
Both vaccines aim to protect people from a virus that is basically only transmitted when a person engages in what amounts to optional behavior. (Hepatitis B can also be transmitted from mother to child if the mother is carrying the virus. Regardless of the mother's infection status, however, all babies are given that vaccine at birth.)
HPV is not a public health threat in the same way, say, polio is. And that gives state governments much less of a compelling interest to mandate that children be vaccinated for it.
Let's put aside for the purposes of discussion the bizarrely controversial notion that parents should be able to decide what enters their children's body via injection, especially when that shot carries the risk of harm or death.
HPV does not lurk in the air, in swimming pools or on playground equipment. That makes the vaccine's public health credentials dubious at best.
Yes, 3,700 women in the United States die of cervical cancer every year. But just having HPV doesn't mean you're going to get cancer. The FDA said as much in its press release: "For most women, the body's own defense system will clear the virus and infected women do not develop related health problems."
Estimates of the number of people with HPV in the United States vary wildly, but perhaps up to 80 percent of women are infected with HPV at one time or another before they are 50.
Yet given that high incidence, the number of women who develop cervical cancer is pretty low, about 10,000 cases each year. Pap smears usually catch abnormal cells before cancer has progressed, when women are treated with extraordinarily high rates of success.
According to Dr. Herschel W. Lawson of the CDC, the greatest risk factor (60 percent) for cervical cancer in the U.S. is not being screened or being screened at intervals greater than 5 years.
So uncommon is cervical cancer in the United States that it is listed as a rare disease by the National Institutes of Health. That's not to say that it's not painful or tragic for thousands of women, but it's nonetheless relatively rare. There's a reason that just about every prediction about a reduction in cervical cancer due to the HPV vaccine is reported as a worldwide statistic. The numbers in the U.S. are just not that high as a percentage of the population.
Most women in the U.S. who develop invasive cervical cancer have not had regular pap smears, according to the CDC. So to say that because 3,700 women in the United States die of cervical cancer every year, and thus there's an urgent public-health need to vaccinate every adolescent girl -- without mentioning that many if not most of those women did not have regular screenings -- is somewhat disingenuous.
But even if the vaccine proves to be successful at reducing overall HPV infection, and the reduced number of HPV infections lead to a correlating decline in cervical cancer cases -- both still assumptions at this point, as the vaccine hasn't been studied nearly long enough to determine that -- some parents still may not want to give it to their daughters.
For starters, it could cause harm. All vaccines carry the risk of injury or death.
Additionally, the FDA's insert reveals that nine people developed arthritis after receiving the vaccine versus three for the placebo, out of approximately 21,000 individuals in that trial. Nine kids with arthritis after receiving the vaccine might not seem like a big deal in the grand scheme of things. After all, arthritis is better than cancer, right? That depends.
Given the fact that cervical cancer is relatively rare, highly preventable and most often successfully treated early on, maybe the risk of arthritis -- a painful and often debilitating disease -- isn't a worthwhile tradeoff. Isn't that for parents to decide?
And maybe we won't know the true incidence of harmful effects until the vaccine is given to millions, rather than thousands, of children and young adults.
Suzanne Nelson is a freelance journalist and writer living in New Orleans. She spent five years covering Congress for Roll Call Newspaper in Washington, D.C., and now focuses on subjects pertaining to health.
She also maintains a health blog at honesthuman.com.
