Twenty years after the approval of the first vaccines against human papillomavirus (HPV), studies continue to find new benefits.
Although HPV vaccines are best known for preventing cervical cancer in women, a large new study shows that the shots are also associated with a dramatic drop in the risk of HPV-related cancers in men and boys, too.
Men and boys who received the HPV vaccine from ages nine to 26 were nearly 50% less likely to develop cancers of the head and neck, esophagus, anus, or penis, according to a study published last week in JAMA Oncology. Vaccinated participants in the study were given shots that prevent infection with nine strains of HPV.
The results show the importance of vaccinating all children and teens against HPV, said Taito Kitano, DrPH, first author of the study and a researcher at Nara Prefecture General Medical Center in Nara, Japan.
“Children, adolescents, parents and health care workers should be more informed about the expected benefits of HPV vaccine, not just cervical cancer,” Kitano said.
The results are “absolutely fantastic,” said Oliver Brooks, MD, a pediatrician and spokesman for the National Foundation for Infectious Diseases, who was not involved in the research. Brooks said he was impressed by the size of the study, which included more than 510,000 boys and men vaccinated between January 2016 and December 2024, along with an equal number of unvaccinated males.
“The new study provides the strongest evidence yet that HPV vaccines protect men as well as women,” Brooks said. “This is a vaccine that is preventing cancer in a major way.” (See related CIDRAP News story today for full study details.)
This is a vaccine that is preventing cancer in a major way.
Although cervical cancer screening can prevent cancer and save lives, there are no early detection programs for other types of HPV-related malignancies, said Otis Brawley, MD, a professor of oncology at the Johns Hopkins University School of Medicine who was not involved in the new study.
That makes preventing these cancers essential.
“HPV vaccines could be even more of a game-changer for these other cancers than for cervical cancer,” Brawley said.
Millions of infections a year
HPV is ubiquitous, infecting almost everyone who has had sex. More than 42 million Americans are infected with types of HPV that are known to cause disease, according to the Centers for Disease Control and Prevention (CDC). About 13 million Americans, including teens, become infected each year with the virus, which is shared through sexual contact.
In most cases, the immune system neutralizes the virus. But about 1% of people develop chronic infections, which dramatically increase the risk of cancer.
Nearly 40,000 Americans a year are diagnosed with a malignancy caused by HPV, which causes more than 90% of tumors of the cervix, as well as most cancers of the vagina, vulva, head and neck, penis, and anus.
Preventing cancer
Cervical cancer screenings, which allow health care providers to detect and remove both cancers and precancers, have cut mortality rates for the disease in half in recent decades.
Cervical cancer rates and deaths are falling fastest in the generation of women who were eligible to be vaccinated. Cervical cancer incidence fell 65% from 2012 to 2019 among US women younger than 25 years. In the same age-group, cervical cancer deaths declined by 62% from 2013-2015 to 2019-2021.
It’s good news, because it will change what people think about HPV vaccines.
The picture is very different for other cancers caused by HPV.
HPV-related head and neck cancers, which often develop in the back of the mouth and throat, are typically found only after they cause symptoms, such as a pain or swelling. By that time, head and neck cancers are often larger and more advanced, making them harder to cure, Brawley said. Therapy can be painful, making it difficult or impossible for people to eat or drink during treatment. The new study could help convince more young men and their parents of the value of HPV vaccines, Brawley said.
“This is exciting,” Brawley said. “It’s good news, because it will change what people think about HPV vaccines.”
Protecting more children
When the Food and Drug Administration approved the first HPV vaccine in 2006, the shots were recommended for girls to prevent cervical cancer and genital warts. The FDA approved the shots for boys in 2009, although they weren’t broadly rolled out for boys until 2012, after an official CDC recommendation. The CDC has also expanded the age range for HPV vaccination over the years. Although the shots are recommended for children at ages 11 to 12—an age when kids get other shots—the CDC allows children to be vaccinated as early as 9 and as late as 45.
Although the first HPV shots prevented infection from two to four strains of HPV, current vaccines protect against nine, which together prevent 90% of cervical cancers.
More than 300 million doses of the HPV vaccines have been administered around the world over the past two decades.
As time goes by, scientists continue to learn more about the vaccine’s benefits:
Barriers to protecting the youngest generation
When the vaccines were first introduced, some parents were reluctant to vaccinate their children because they were afraid the shots would encourage young people to have sex.
Twenty years later, there’s no sign that HPV shots encouraged teens to take sexual risks. According to the CDC’s 2023 Youth Risk Behavior Survey, adolescent sexual activity has declined since 2013.
Yet in the United States, HPV vaccination efforts appear to have stalled. Coverage among teens remained unchanged from 2022 to 2024, with 78.2% receiving one or more doses and 62.9% reporting they had received all recommended doses.
And in spite of two decades of efforts to educate people about HPV, a survey published last August in JAMA Oncology found that more than a third of US adults are unfamiliar with HPV. Many people who answered the survey were unaware of the HPV vaccine, and more than 70% were unaware that HPV causes oral cancers.
Anti-vaccine sentiment could imperil progress
Some people are confused by misinformation about HPV vaccines, as well.
Health and Human Services Secretary Robert F. Kennedy Jr. has called HPV shots “dangerous and defective,” in spite of an abundance of data showing them to be remarkably effective and safe.
An influential CDC advisory panel, whose members were handpicked by Kennedy, last year announced plans to review the HPV vaccine’s safety and efficacy. Although that panel, the Advisory Committee on Immunization Practices, has been disbanded due to a federal judge’s decision, the Trump administration recently drafted a new charter for the group.
Some public health groups have expressed concern that Kennedy aims to fill a new advisory committee with anti-vaccine activists, rather than scientific experts.
