Cervical Precancers Drop Since Introduction of HPV Vaccine

A study using data from the Centers for Disease Control and Prevention (CDC) provides evidence that the human papillomavirus (HPV) vaccine is effectively reducing the numbers of cervical precancers – lesions that can become cervical cancers. The study was published February 21, 2019 in Cancer Epidemiology, Biomarkers, & Prevention.

Cervical cancer is the most common cancer linked to HPV in women. Nearly all cervical cancers are caused by HPV, and most of them are caused by types 16 and 18. The HPV vaccine can protect people from the types of HPV infections that can cause cervical cancer as well as cancers of the vulva, vagina, penis, anus, and throat.

This study focused on a time period that began 2 years after the first HPV vaccine was introduced and ended a year before the newer, current vaccine was approved. The first vaccine protected against HPV types 16 and 18. The vaccine now used in the US protects against 9 types of HPV, including 16 and 18. The study included women who had been vaccinated and those who had not and found that cervical precancers caused by HPV types 16 and 18 have declined.  

The researchers tested tissue samples collected between 2008 and 2014 from more than 10,000 women ages 18 to 39 years who were diagnosed with cervical precancers. They found:

  • The percentage of precancers caused by HPV types 16 and 18 declined from 52.7% in 2008 to 44.1% in 2014.
  • Among women who had been vaccinated, the percentage of precancers caused by HPV 16 and 18 dropped from 55.2% to 33.3%.
  • In unvaccinated women, the percentage dropped from 51% to 47.3%.

The decline was biggest among women who had been vaccinated, but unvaccinated women also showed a decline. The study authors say this suggests herd protection, which happens when enough people in a community are vaccinated and it’s harder for the virus to travel from person to person.

HPV and HPV Vaccination

The CDC and the American Cancer Society recommend girls and boys begin getting the vaccine series at age 11 or 12, and catch-up vaccination through age 26. The vaccination series can also be started as early as age 9.

According to the CDC, in 2016, 65% of girls ages 13 to 17 years had received the first dose of the HPV vaccine and 49.5% had completed the vaccination series.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Trends in Human Papillomavirus Vaccine Types 16 and 18 in Cervical Precancers, 2008–2014. Published February 21, 2019 in Cancer Epidemiology, Biomarkers & Prevention. First author Nancy M. McClung, PhD, RN, Centers for Disease Control and Prevention, Atlanta, Ga.

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