Of all the vaccines I give adolescents, the one that parents are most likely to refuse is the vaccine against human papilloma virus, or HPV. This puzzles and frustrates me, because the vaccine can help prevent their children from getting cancer.
Millions Are Infected
HPV is the most common sexually transmitted infection. And it is the main cause of cervical cancer. About 79 million Americans are currently infected with HPV. About 14 million people become newly infected each year. HPV is so common that nearly all sexually active men and women will get at least one type of HPV at some point in their lives. According to the U.S. Centers for Disease Control and Prevention, every year HPV causes 19,000 cancers in women and 9,000 cancers in men.
There are about a hundred different strains of the virus; 15 of them are known to cause cancer. Four strains — 16, 18, 31, and 45 — cause 80% of the cancer we see. Two strains, 6 and 11, cause most genital warts.
The HPV vaccine can make a big difference. In fact, a 2013 study showed that since we started giving the vaccine routinely in 2006, there has been a 56% drop in the prevalence of the vaccine strains among girls ages 14 to 19 years.
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Why This Vaccine is So Important
About 10,300 women in the United States get cervical cancer each year. It used to be one of the most common causes of cancer deaths in U.S. women.
Between 1955 and 1992, the death rate went down by 74%. That's because of the Papanicolau test, or Pap test as it's generally called. This test, in which some cells are removed from the surface of the cervix and checked for any signs of cancer, allows doctors to catch the cancer early. When caught early, cervical cancer has a 5-year survival rate of 93%.
The problem is, not all women get Pap tests. That's why this vaccine is so important.
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Parents' Concerns About the Vaccine
There are two different forms of the vaccine, Cervarix and Gardasil. While both are effective and have good safety records, Gardasil protects against more strains of HPV, including those that cause genital warts. It has also been shown to protect against cancers of the vulva, vagina and anus. And it is the only one approved for boys.
There are two main worries I hear from parents about the vaccine.
- Safety concerns - Parents hear from friends or read things on the Internet about the vaccine being dangerous. Side effects are possible from any medical treatment, including vaccines. And you can never know for sure how any particular person is going to react to a vaccine (or any medical treatment, for that matter). But extensive studies have shown that for the vast majority of people, the HPV vaccine is safe. Sometimes people feel lightheaded or even faint after getting it, but that can usually be prevented by sitting or lying down for 15-20 minutes afterward. I have never had a patient have a serious side effect from the vaccine.
- Sexual behavior - Some parents worry that giving the vaccine gives the green light for their children to have sex. It's really important to remember that this vaccine is about cancer, not sex. The idea is to give the vaccine well before any sexual activity –and exposure to HPV – begins. And at a time when their parents are taking them to the doctor regularly. This is important because the vaccine is given in 3 doses over 6 months. While the vaccine can be given as early as 9 years old, most of the time we give it at age 11 or 12, along with the TdaP and Menactra vaccines. It can be given up to age 26 in women and 21 in men, but at that point many people are already exposed to HPV.
We certainly do not know everything there is to know about HPV, cervical cancer or vaccines. But over the past several years, we've had a chance to gain more experience with the HPV vaccine. What we see is very promising.
So if you have an adolescent child, talk to your doctor about the HPV vaccine. After all, anything we can do to prevent cancer in our children is a good thing.
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Claire McCarthy, M.D., is an assistant professor in pediatrics at Harvard Medical School, an attending physician at Children's Hospital of Boston, and medical director of the Martha Eliot Health Center, a neighborhood health service of Children's Hospital. She is a senior medical editor for Harvard Health Publications.