If you could give your child a vaccine that would undeniably reduce the risk of certain types of cancer, would you do it? Of course you would, especially if you were assured by your board-certified pediatrician that the vaccine was effective and safe. But in the United States, two vaccines — Gardasil and Cervatrix — that prevent cervical cancer in women, penile cancer in men, and oral (tongue and throat) cancer in both men and women have still not caught on after first becoming available 10 years ago. Why that is continues to confound public health experts and pediatricians.
Human papillomavirus (HPV) is an infection transmitted by any sexual contact, including simple skin-to-skin touching. The most common sexually-transmitted infection in humans, it is very contagious, resulting in more than 14 million infections annually, mostly in teenagers and young adults. Most often, infection results in no symptoms. But many HPV infections result in genital warts, which are uncomfortable, embarrassing, and often painful to treat. (All warts, by the way, are caused by viruses.) The cancers caused by this virus are no fun, either. According to the CDC, HPV-caused cancers are common and deadly:
Every year, over 27,000 women and men are affected by a cancer caused by HPV— that’s a new case every 20 minutes.
Persistent HPV infection can cause cervical and other cancers including:
- Cervical cancer: The most common HPV cancer. Almost all cervical cancer is caused by HPV.
- Vulvar cancer: About 69% are linked to HPV.
- Vaginal cancer: About 75% are linked to HPV.
- Penile cancer: About 63% are linked to HPV.
- Anal cancer: About 91% are linked to HPV.
- Cancer of the back of the throat: About 72% are linked to HPV.
In 2012, more than 12,000 American women were diagnosed with cervical cancer; one-third (4,074) of cervical cancer patients died. Globally, death rates from cervical cancer are even higher.
Who wouldn’t want a safe and effective vaccine to prevent this scourge? Many American parents, answers Jan Hoffman:
Despite the vaccine’s proven effectiveness, immunization rates remain low — about 40 percent of girls and 20 percent of boys between the ages of 13 and 17. That is partly because of the implicit association of the vaccine with adolescent sexual activity, rather than with its explicit purpose: cancer prevention. Only Virginia, Rhode Island and the District of Columbia require the HPV vaccine.
Recent efforts have focused on recommending the vaccine for children ages 11 and 12, when their immune response is more robust than that of teenagers and when most states require two other vaccines — one for tetanus, diphtheria and pertussis, and the other for meningococcal disease. The immunization rates for those vaccines are 80 percent and higher.
Contrasted to some other countries, these low HPV immunization rates are extraordinary and abysmal, unprecedented in our nation’s medical history. Rwanda’s immunization rate against HPV is 93%. Rwanda!
A new study, published this month in Pediatrics, demonstrates the high efficacy of HPV vaccine. Despite such low vaccination rates in the U.S., Alice Park says immunizing teenagers has so far been extremely effective:
Now, in a study published in Pediatrics, Dr. Lauri Markowitz and her colleagues show how critical the vaccine can be to health. They report that rates of HPV infection among teens ages 14 to 19 dropped by 64% six years after the shot was recommended, and by 34% among people ages 20 to 24.
What’s interesting about the decline, says Markowitz, is that it’s much larger than she would have expected given the relatively low rates of HPV vaccination…
It will take at least a decade or more before researchers can see whether the HPV vaccine is helping to lower cervical cancer rates, since that cancer generally doesn’t develop until mid-life. But there are hopeful signs that with lower infection rates, lower cancer rates will follow. Already, other studies have found declines in genital warts and drops in precancerous lesions in the cervix. “HPV is one of the most effective vaccines we have in our immunization program,” says Markowitz. “If we had higher coverage, we would have even more impact.”
More information on The PediaBlog about HPV infections and protection with HPV vaccines here.