The HPV vaccine can protect against cancer-causing forms of this sexually-transmitted infection. Despite this, some families opt to forego giving it to their children for a variety of reasons.

While a common one is the contention that it encourages girls and boys to be more sexually active, the persistent—though unfounded—belief that the HPV vaccine can cause ovarian failure in young women has helped fuel lower-than-expected turnout rates among American schoolchildren.

According to the Centers for Disease Control and Prevention (CDC), in 2017, approximately 49% of adolescents were up-to-date with their HPV vaccinations and 66% of those ages 13 to 17 received the first dose of the vaccine series.

How the Rumors Began

In 2014, researchers in New South Wales, Australia reported that three girls, ages 16 to 18, experienced ovarian failure after receiving the quadrivalent HPV vaccine.

The girls, who were unrelated and lived in different locations, had each been given oral contraceptives to treat menstrual cycle abnormalities prior to their diagnosis. The only other commonality the researchers could find was HPV vaccination, which they suggested preceded the ovarian decline.

The researchers asserted that these identified cases of ovarian failure warranted further research. They noted that postmarking surveillance has its limitations, such as not accurately representing diagnoses when adverse events are reported.

The suggestions were almost immediately criticized. Not only did the report focus on only three isolated cases, but it did not involve a full investigation of other potential causes beyond the HPV vaccine.

Moreover, no such association had ever been noted in national surveillance despite the fact that 80% of girls and 76% of boys in Australia were vaccinated against HPV.

Even so, anti-vaccine advocates were quick to leap on the report and circulate it through social media as “proof” of HPV vaccination harm.

What the Research Shows

Ovarian failure is not seen to be a potential risk of HPV vaccination.

A 2018 review published in the journal Pediatrics found “no significant elevated risk” of ovarian failure in nearly 200,000 young women who received the HPV vaccine. The authors went on to say that this should lessen worries about reduced fertility due to the vaccine.

Likewise, a 2020 review of data from the 2013-2016 National Health and Nutrition Examination Survey noted that there was “no evidence of increased infertility among women who received the HPV vaccine.”

For the vast majority of adolescents, the worst side effect is a sore arm and headache. Fainting has also been known to occur.

On very rare occasions, a serious whole-body allergy known as anaphylaxis has been reported following vaccination.

Pre-Approval Testing

Some level of concern about drug safety is understandable. After all, there have been drugs approved by the U.S. Food and Drug Administration (FDA) that have been shown in later years to be unsafe.

With that said, the process of approval is a long and thorough one.

Before a vaccine is allowed to be administered for widespread use in the United States, it first has to go through a series of rigorous tests in humans. During these pre-licensure clinical trials, the vaccine is tested in thousands of people to assess not only its efficacy but its safety.

This involves blinded research in which participants are randomly selected to receive either the vaccine or a placebo. By comparing the results between both groups, scientists are able to get a clear idea of the benefits and risks of the vaccine.

If, and only if, the vaccine is shown to have strong benefits and minimal risks can it be approved by the FDA for use in the United States. Getting to this point can take years; many vaccine candidates never make it this far.

The only exception to this is when an emergency use authorization (EUA) is granted during a public health crisis.

Gardasil 9, which is the only HPV vaccine currently used in the U.S., underwent years of extensive safety testing before it received full approval from the FDA.

Monitoring for Safety

Once a vaccine has been licensed, a group within the CDC called the Advisory Committee on Immunization Practices (ACIP) makes recommendations on who should receive it.

Researchers, meanwhile, continue to verify that the vaccine is safe. Through systems like the Vaccine Adverse Event Reporting System (VAERS) and the Vaccine Safety Datalink, the CDC can collect and analyze data on adverse events.

If any concerning patterns emerge, the ACIP reviews the findings and adjusts their recommendations accordingly, if needed.

In the case of the HPV vaccine, thousands of people from around the world were included in the pre-market trials, while hundreds of thousands have been included in post-market studies. Research continues to show that the HPV vaccine is overwhelmingly safe and effective at reducing cancer-causing HPV infections.

HPV Vaccination Recommendations

Approximately 85% of people in the United States will get an HPV infection in their lifetime. While most infections will clear with no long-term consequences, some people will go on to develop cancer as a result.

Experts have identified several strains of HPV that are more likely to cause cancer, and that information was used in creation of the vaccine.

Cervical cancer is the most well-known cancer associated with HPV infection, but HPV can cause at least six other kinds of cancer in both men and women. They include anal, penile, vaginal, vulvar, and head and neck cancers.

In fact, HPV is believed to be linked to 5% of all cancers worldwide.

Although the CDC does not recommend vaccination for everyone over the age of 26, people ages 27 to 45 can decide to get vaccinated based on consultation with their doctor.

Girls and boys age 11 or 12, as part of their childhood vaccination schedule Children and adults ages 9 through 26 who have not been previously vaccinated

The HPV vaccine is administered in two or three doses, depending on when you start the series. Younger adolescents need only two doses, while those who start at age 15 or older (or who are immunocompromised) will need to get three.

Why Vaccinate So Young?

HPV vaccination is the best means to protect against high-risk subtypes of HPV.

Early adolescence is the best time to get vaccinated for several reasons:

Because the vaccine can only protect against HPV types the body hasn’t yet encountered, it is best to complete the series before most adolescents are sexually active. The vaccine produces a stronger immune response at a younger age compared to older ages. Adolescents are already receiving vaccines against diseases, including meningitis and tetanus, at ages 11 and 12. It makes practical sense to give the HPV vaccine at the same time.

A Word From Verywell 

The benefits of HPV vaccination—preventing cancer and reducing the risk of HPV transmission—overwhelmingly outweigh the risks.

Talk to your child’s doctor about HPV vaccination at age 11 or 12 so you can best protect them from potential disease.