When people hear about vaccine deniers — anti-vaxxers, to some — they most often think about parents who are refusing to vaccinate their children. But there’s another type of vaccine refusal, and it’s important that we not ignore that. Doctors sometimes promote the use of some vaccines with less enthusiasm than others. Sometimes, they don’t talk about them at all.

This occurs most often with the human papillomavirus, or HPV, vaccine. The low immunization rates with this vaccine, and the behaviors of the physicians who might be contributing to that, have consequences.

HPV is a sexually transmitted infection that is very, very common, so much so that almost all sexually active people will get at least one of more than 40 types at some point in their lives. The C.D.C. estimates that almost 80 million Americans are currently infected with HPV, and that about 14 million people will become newly infected this year.

Most people don’t suffer any real negative health consequences. But some do. About 1 percent of those infected will have genital warts at any given moment. More important, about 17,500 women and 9,300 men will be affected by cancers that HPV causes each year. These include cervical, oropharyngeal, anal, vaginal and penile cancers.