Is there evidence that the HPV vaccine prevents cancer?

Infectious Diseases Reproductive Health Vaccines

Yes! New evidence released in 2020 showed a dramatically reduced risk of cervical cancer among people who took a quadrivalent HPV vaccine.

Risk was *much* lower for those who took the vaccine before age 17. HPV vaccination is recommended at age 11 for all genders. Yes, for girls and boys too!

Don’t pass this one up–get it along with your other middle school vaccines. And if you missed it, you can still get it–and still get some benefit. It’s recommended as a routine vaccination through age 26, and it may be available up to age 45 if you talk to your clinician.


Context: We already know that the HPV vaccine prevents HPV infection. In fact, this was the main benefit shown in the original, pre-market studies for the HPV vaccine which were reviewed when it was first approved for use. However, since HPV infection does not *always* lead to cervical cancer–and when it does, it takes many years–up until recently there was still some question about how well the HPV vaccine would prevent cervical cancer itself.

To answer this question, researchers used Swedish demographic and health records on more than 1.7 million girls and women*. They compared the rate of invasive cervical cancer for women who got the HPV vaccine and those who did not. Among those who did get it, they were able to compare women who were vaccinated before age 17 versus those who were vaccinated between ages 17 and 30.

They found that women who had been vaccinated with the quadrivalent HPV vaccine between ages 10 and 17 had a cumulative incidence rate of 4 cases of invasive cervical cancer per 100,000 through age 28. That means there were 4 cases per 100,000 women in this group during the whole follow-up time of the study, which covered from 2006 when the vaccine was approved through the participants’ age 28.

There were 54 invasive cervical cases per 100,000 in people who were vaccinated between ages 17 and 30.

There were 94 invasive cervical cancer cases per 100,000 among people who were 10-30 years old during the study time window and who were not vaccinated against HPV.

What do the authors make of the difference in effectiveness for people vaccinated earlier versus later in their lives? They say “Our results … support the recommendation to administer quadrivalent HPV vaccine before exposure to HPV infection to achieve the most substantial benefit, since vaccination has no therapeutic effect against preexisting HPV infection.” In other words, earlier is better because it works best to vaccinate well before any exposure to HPV. Once you’ve been infected, the vaccine does not prevent the progression of HPV to cancer. However, even for those vaccinated later, it cut the risk nearly in half.

A study released in 2018 also showed that cervical cancer has started to decline in the United States since the introduction of the HPV vaccine, but couldn’t show an individual-level reduction in cancer risk for those vaccinated.

Note that the original study does not distinguish between girls/women and people who are at risk of cervical cancer due to their biology.

Stay safe. Stay well.

Those Nerdy Girls