The good news is that the HPV vaccine can prevent cancer. The bad news is that parents are not getting their children vaccinated.

Nearly 80 million people in the United States are infected with the human papillomavirus (HPV). In most people, the virus produces no symptoms, yet causes an estimated 34,700 cancers every year. The current HPV vaccine protects against seven different strains of HPV and the cancers connected to the virus.

The best time for children to be vaccinated against HPV is as 11- or 12-year-olds. Yet only about 16 percent of kids this age have gotten the vaccine, a recent study shows.

There are several good reasons to get the vaccine during the preteen years, at age 11 or 12. For one, the body's immune response to the vaccine is stronger at younger ages.

Later is much better than never for the HPV vaccine. The Centers for Disease Control and Prevention (CDC) recommends it for young women and men through age 26, and urges parents of teens who haven’t gotten the HPV vaccine to talk to their doctor about doing so as soon as possible.

There are several good reasons to be vaccinated during the preteen years, at age 11 or 12. The body's immune response to the vaccine is stronger at younger ages. And because the HPV vaccine can be given at the same time as two other vaccines 11- to 12-year-olds are supposed to get, tetanus/diphtheria/pertussis and the meningococcus vaccine, it is easy to schedule.

Because of their stronger immune response, children under 15 require only two doses. After age 15, they need three shots.

Human papillomavirus is spread through sexual contact. Unlike other sexually transmitted infections, however, it can be be passed by skin-to-skin contact. So it's better to give the vaccine before teens become sexually active. One set of estimates has girls over five times more likely to become sexually active by age 15 than by age 13 and boys more than three times as likely. So earlier vaccination makes a lot of sense.

More teens are getting vaccinated for HPV than in previous years. But the vaccination rate is still woefully low and happened later than recommended. According to information from 2016, an estimated 43.4 percent of 13-to-17-year-olds were fully vaccinated against HPV.

The authors don't single out who is responsible for the low vaccination rate, but clearly parents and doctors are not communicating well about the vaccine. Like many other doctor-patient issues, it may be up to the patient (or parent) to break the ice.

For more details, including state-by-state comparisons, see the article, which appears in the Journal of Infectious Diseases.