Only about half of teenage girls receive the human papillomavirus (HPV) vaccine at the recommended age, according to a recent study.

The HPV vaccine protects against a virus that is responsible for almost all cases of cervical cancer. It is responsible for 99.7 percent of cervical cancers and several other cancers. The HPV vaccine protects against 70 percent of cervical cancers and 90 percent of genital warts cases.

The Centers for Disease Control and Prevention (CDC) has recommended that girls get the vaccine when they are 11 or 12 years old, because it is most effective when it is given before girls become sexually active.

"Rates of HPV infection increase significantly every year for young people between 14 and 24, so vaccination at a young age is very important," Mahbubur Rahman, who led the study, said in a statement.

For the study, researchers analyzed data from the annual National Immunization Survey of Teens conducted by the CDC. The CDC data tracked information from 2008 to 2012 on girls' ages when the vaccine series was started and completed.

Their findings indicate that, among those who were vaccinated, only 14 percent of girls began the three-dose vaccine series at the CDC's recommended age of 11 to 12 in 2008. By 2012, this proportion rose to 56 percent. However, this means that almost half of the surveyed teenage girls still received the vaccine older than 12. Researchers are not certain how effective the vaccine is when it is given after this age. These trends did not differ by race/ethnicity.


"It's important that parents and health care providers are aware of the importance of early HPV vaccination to ensure that girls receive this vaccination at the CDC's recommended age," Rahman added.

The findings are detailed in the journal Vaccine.