HPV is associated with almost every case of cervical cancer.
At least 79 million Americans, mostly in their late teens and early 20s, are infected with HPV, the most common sexually transmitted infection. Yet parents aren't vaccinating their teens in near the numbers the Centers for Disease Control and Prevention reporting would like to see — only 49% of teens between the ages of 13 and 17 are receiving the recommended dosage.
Much of the country requires parental consent for those under the age of 18 to receive vaccinations.
So some states have attempted to change that by allowing teens to obtain the HPV vaccine without Mom or Dad.
Teens saying 'yes' when parents say 'no'
Giving teens a way to say yes to a vaccine may be giving them a way to save their lives, according to growing body of evidence.
A meta-analysis of more than 600 studies of HPV vaccination funded by the World Health Organization found a decline in HPV and in growths.
Prof. Marc Brisson of Université Laval in Quebec, who led the review, said cervical cancer could be eradicated, "if sufficiently high-vaccination coverage can be achieved and maintained."
As New Jersey was dealing with the with the spread of measles, a bill was introduced in May that would allow teens as young as 14 to be vaccinated against a number of diseases, including HPV, without parental consent. It failed.
New York state Assembly and Senate lawmakers have failed to pass bills since 2009 allowing teens to consent on their own to being vaccinated for both HPV and hepatitis B. They tried again this year and it failed.
"Anything related to children having sex tends to be a detriment for legislation," Assemblywoman Amy Paulin told NBC News. Paulin, who introduced the legislation, said she plans to try again next year.
Still, states still have found ways for teens to get vaccinated by turning to health departments instead of waiting for laws to change.
The New York Department of Health has been allowing teens to get the HPV shot since 2017.
California; Delaware; New York; and Washington, D.C., allow regulations permitting teens under 18 to be vaccinated against sexually transmitted diseases, including HPV.
The National Center for Youth Law says regulations and statutes could be interpreted in other states that would allow this right to minors. They are Alabama, Arkansas, Idaho, Iowa, Kansas, Montana, North Carolina, Oklahoma, South Dakota and South Carolina.
Why some parents are wary
The CDC recommends that the HPV vaccine be given in two shots for girls and boys ages 11 and 12, six to 12 months apart.
The shots are more effective if the child never has been exposed to the viruses, so before they become sexually active. HPV, which is spread through sexual intercourse, is extremely common in America, affecting about one in four people, according to the CDC.
A primary reason that parents give for not vaccinating is fear that their children will have risky sex, according to a study published in the Canadian Medical Association Journal.
This is true even among parents who supported other childhood vaccinations, such as one for measles.
But that fear is not supported by a 2015 study. JAMA research found that while up to 20% of parents worried that getting the vaccine may lead to not using condoms, infection rates rose at the same pace in vaccinated and unvaccinated girls.
"This is probably the most definitive evidence yet that vaccinating your child against HPV is unlikely to lead them to be more sexually active, at least in an unsafe way," said Anupam Jena, a Harvard Medical School researcher.
The HPV vaccine, also know by the brand name Gardasil, first became available in 2006.
This article originally appeared on USA TODAY: HPV vaccines without parental consent? Some states are finding ways