Why are adolescents and their parents embracing meningococcal and Tdap vaccines but not the HPV vaccine? One possible explanation is a clash between perception and reality, People just don’t understand how serious an infection HPV can be. In a typical year in the United States about 150 people die from meningococcus, four from tetanus, none from diphtheria, 20 from pertussis, and roughly 4,000 from cancers caused by HPV. People are more than 20 times more likely to die from HPV than from the other four diseases combined.

About 79 million people in the United States have been infected with HPV, and 14 million new infections occur every year. As a consequence, 18,000 women and 8,000 men suffer preventable cancers of the cervix, anus, penis and throat; it’s the most common, and except for H.I.V., the most fatal sexually transmitted disease.

Another common misperception is that the HPV vaccine is ineffective and immunity is short-lived. But the truth is that the HPV vaccine is virtually 100 percent effective at preventing the precancerous lesions caused by the types of HPV contained in the vaccine, which would most likely prevent most cervical cancers. Regarding how long immunity will last, the HPV vaccine is made in the same manner as the hepatitis B vaccine, for which immunity lasts at least 30 years. Immunity provided by the HPV vaccine is likely to be no different.

Further, some high-profile — and highly irresponsible — claims have been made that the vaccine is unsafe. The HPV vaccine has now been studied in more than a million women to determine whether it causes any serious side effects. It doesn’t. There is no scientific support for the suggestion by the onetime presidential hopeful Michele Bachmann that the HPV vaccine could cause “mental retardation,” or for Katie Couric’s giving voice to the notion that it may have caused illnesses and death.

Finally, some fear that the HPV vaccine may increase sexual promiscuity. A study of 1,243 young women and girls between the ages of 15 and 24 alleviated this concern. Those who received the HPV vaccine were not more likely to engage in risky sexual behavior. Nor did it make sense that they would. The HPV vaccine doesn’t prevent other sexually transmitted diseases, like chlamydia, gonorrhea, herpes and syphilis. Indeed, the HPV vaccine doesn’t even prevent all types of HPV, just the majority of those most likely to cause cancer. This argument would be analogous to the claim that people who received a tetanus vaccine could run across a bed of rusty nails with impunity.