Thursday, October 7, 2010

Teens and vaccines: What's important?

We tend to think about vaccines in terms of how they affect our very young children. But pre-teens and teenagers are supposed to receive a raft of immunizations, too. A vaccine-autism link isn't the issue at this stage, but many questions still remain about which shots are important -- and if some of them are necessary at all.

According to the US Centers for Disease Control and Prevention, doctors recommend that all 11- and 12-year-olds get the single-dose Tdap and meningococcal vaccines, as well as a yearly flu shot. The National Menengitis Association is emphasising the importance of the meningococcal vaccine for children age 11 to 18 -- though their informational site,, and materials for its program are "supported by unrestricted educational grants" from GlaxoSmithKline, Merck & Co., Inc., and Novartis Vaccines, according to the fine print on the website itself. (My request to their PR person for statistics and information from sources other than vaccine manufacturers got no response, though WebMD reports that, of the 1,000 to 2,600 who get meningococcal disease each year, one-third are teens and young adults, and 10 percent to 15 percent of those who gets sick will die from it, in spite of antibiotics.)

The CDC also recommends a three-shot series to protect girls as young as 9 against the human papillomavirus, or HPV, some forms of which can cause gential warts and cervical cancer. And yes, there's plenty of controversy around the idea of protecting 9-year-olds against a sexually transmitted disease -- especially when the protection hasn't yet been proven to last and, according to some reports, may cause some serious side effects.

HPV is spread by skin-to-skin and sexual contact, and while there are more than 100 types of HPV out there, only 15 or so cause cancer. And, in most women, almost all HPV infections are cleared by the immune system naturally. "Even if persistently infected with HPV, a woman most likely will not develop cancer if she is regularly screened," Dr. Charlotte Haug writes in an editorial in the Aug. 2009 issue of The Journal of the American Medical Association. Dr. Haug also points out that while HPV is the most prevalent sexually transmitted infection today, "the relationship between infection at a young age and development of cancer 20 to 40 years later is not known" and "the true effect of the vaccine can be determined only through clinical trials and long-term follow-up." (The entire article is an eye-opening read; you can find it here.)

The campaign to vaccinate young girls against it is pretty persuasive. "Each year in the US, thousands of women learn they have cervical cancer," says the confident girl holding the skateboard in one TV commercial. "I could be one less. One less statistic." She's edgy and cool, posed at the top of the half pipe, but getting cervical cancer isn't a risk she's willing to take.

But what if there's not that much of a risk to begin with?

Unlike with diseases like the measles or the mumps, herd immunity isn't in jeopardy here -- the number of cases of cervical cancer aren't going to skyrocket if our daughters aren't immunized. And last year, a government study linked one of the HPV vaccines, Gardasil, to 32 unconfirmed deaths and other serious but rare side effects.

"The rate of serious adverse events [with Gardasil] is greater than the incidence rate of cervical cancer,"  Dr. Diane Harper, director of the Gynecologic Cancer Prevention Research Group at the University of Missouri and the lead developer of the HPV vaccine, said at a vaccine conference last year. Incidents of cervical cancer in the US are so low that "even if we get the vaccine and continue PAP screening, we will not lower the rate of cervical cancer in the US,”  Harper said.

Catherine Ruhl, a certified nurse-midwife who is Director of Women's Health Programs at The Association of Women's Health, Obstetric and Neonatal Nurses (AWHONN), recommends the vaccine but acknowledges that the chances of getting cervical cancer are low for girls in the targeted age group.  "Cervical cancer grows very slowly from HPV changes," she says. "It's extremely rare in the 15 to 19 year age group. But HPV is very common once teens start to have sex, though."

Which is why the CDC wants girls to get vaccinated before they become sexually active. There are no easily recognizable signs of infection, since it affects the cervix, but some strains of the virus -- about 40 out of the 100 strains out there -- also cause genital warts in both men and women. According to, the vaccine has recently been cleared for (though is not yet officially recommended for) males ages 9 to 26, who may be carriers of some strains of HPV. Gardasil protects against the two of the 40 that causes most of them, Cervarix does not protect against any of them.

I wrote about the HPV vaccine over at Child Caring earlier this year, and the discussion that sprang up in the comments was pretty intense (you can read through the thread here). Some parents wrote in to describe their daughters' terrible experiences with the series of shots; others chided them, insisting that their children had no trouble with theirs. Some insisted that it's not meant to be a cure for cancer (true) but that it is meant to be a cure for HPV (not true). Another commenter offered up more quotes from lead HPV vaccine developer Dr. Diane Harper, including this one: "It is silly to mandate vaccination of 11- to 12-year-old girls There also is not enough evidence gathered on side effects to know that safety is not an issue. This vaccine has not been tested in little girls for efficacy. At 11, these girls don't get cervical cancer - they won't know for 25 years if they will get cervical cancer. ...To mandate now is simply to Merck's benefit, and only to Merck's benefit."

Of course, no one wants their child to become a statistic. Since HPV is transmitted by skin-to-skin contact, the best way to avoid it is by not engaging in any sort of sexual activity. Quitting or avoiding smoking cigarettes can also decrease your risk, Ruhl points out.  "Cigarette smoking is associated with accelerating the changes caused by HPV on the cervix," she says.

So what can you do to protect your kids? "I think the best choice is giving knowledge to your children, and making sure that they understand about health and safe choices and options," Ruhl says. "And where they go with that is going to be, especially as they get older, their decision."

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