Q: What is the human papilloma-virus, and who should be vaccinated for it?

A: Human papillomavirus (HPV) can cause certain types of cancer, including cervical cancer. Healthcare providers recommend that boys and girls between the ages of 9 and 26 get the HPV vaccine.

Like all viruses, HPV causes infection by entering cells and infecting nearby healthy cells.

There are more than 100 types of HPV. About 40 types infect the genital area of men and women and are spread by skin-to-skin contact during vaginal, anal or oral sex.

Genital HPV infection can occur even if you do not have sexual intercourse.

HPV infection is the most common sexually transmitted infection (STI) in the United States.

Almost everyone who is sexually active will get an HPV infection at some point during their life.

Like many other STIs, genital HPV infection often has no signs or symptoms.

The infected person usually is not aware that he or she has been infected and can unknowingly pass the infection to others.

HPV can cause genital warts, which are not cancer and do not turn into cancer.

Warts can be removed with medication or surgery. Several strains of HPV are linked to cancer of the cervix, anus, vagina, penis, mouth and throat.

In most people, the immune system fights most HPV infections and clears them from the body.

If they are not cleared, they can lead to a pre-cancerous condition.

Cervical cancer screening can detect signs of abnormal cell changes of the cervix and allows early treatment so they do not become cancer.

If everyone was vaccinated, up to 90 percent of genital warts and 90 percent of HPV-related cancers would be eliminated.

But a 2016 report found that only 40 percent of teenage girls and less than 25 percent of teenage boys were vaccinated.

Last October, the U.S. Centers for Disease Control and Prevention approved a two-dose HPV vaccine for children under age 15. This replaces the previous three-dose regimen.

Talk to your child’s pediatrician about getting the vaccine during a regular well-child checkup.

Joanne Price Williamson, M.D. is an obstetrician-gynecologist in practice at Provident OB/GYN Associates. She sees patients at the Legacy Center office in Okatie.