Kids more likely to be vaccinated against HPV if doctors offer shots at earlier ages, study finds
Liz Szabo, MAToday at 8:22 a.m.
Human Papillomavirus (HPV)
Childhood Vaccines
When it comes to protecting kids from the human papillomavirus (HPV), earlier vaccination is better, new research shows.
Children are more likely to be fully vaccinated against HPV—a ubiquitous virus that causes six types of cancer— if doctors offer the immunization when kids are 9 or 10 years old, compared with beginning the series of injections at ages 11 or 12, the age when most clinicians now offer the shots.
That’s according to a study presented at IDWeek, a major infectious disease conference in Washington, DC.
By age 13, more than 77% of children in the study who were offered an HPV vaccination at the younger age received at least one dose, and 62% had received both shots, compared with 67% and 45% of kids, respectively, offered the immunization at the older age.
Overall, children offered the HPV shot earlier were more than twice as likely to begin vaccination, as well as complete the two-dose HPV vaccine series, compared with kids offered the immunization at the older age, according to the study, which included 31 pediatric practices in Colorado and California from 2021 to 2026.
The median age at which youngsters completed the two-dose series was 12.2 years among those offered vaccination at an earlier age, compared with 13.3 years among those offered the shots later.
“Parental concerns, pushback, hesitancy, and acceptance didn't really seem to differ between the groups,” said Sean O’Leary, MD, MPH, first author of the study and a professor of pediatrics at the University of Colorado Anschutz School of Medicine, at a press briefing before the conference. “Most parents were receptive to the change.”
HPV uptake in US teens has stagnated
Most parents seemed comfortable with vaccinating their children earlier, O’Leary said.In interviews, clinicians said that their conversations with families were shorter when they offered vaccination at an earlier age, said O’Leary, director of the Colorado Children’s Outcomes Network, a practice-based research network.
The main objection to vaccinating against HPV at ages 9 or 10 came from parents who had told their children that there would be no shots during this visit. Parents “wanted warnings upfront,” in order to better prepare their children, O’Leary said.
Doctors have been looking for ways to increase HPV vaccination.
Although two decades of research show the vaccine is safe, coverage rates among teens have stagnated. Research by the Centers for Disease Control and Prevention (CDC) finds that 78.2% of teens ages 13 to 17 received one or more doses of the HPV vaccine from 2022 to 2024, with 62.9% reporting they had received both recommended doses.
The World Health Organization’s blueprint for eliminating cervical cancer—which is almost always caused by HPV—calls for fully vaccinating 90% of girls against HPV by age 15. HPV also causes cancer in men, including tumors of the throat, penis, and anus.
Earlier shot shifts timing, boosts overall coverage
The new study answers an important question, said Kengo Inagaki, MD, vice chair of IDWeek for the Pediatric Infectious Diseases Society, who was not involved in the new research.Pediatricians have wondered if starting the HPV series at 9 years old would improve overall coverage, or simply shift vaccination to a younger age, said Inagaki, director of the pediatric transplant infectious diseases program at the University of Michigan C.S. Mott Children’s Hospital.
“By doing this randomized trial, investigators were able to prove that early initiation of vaccination does both of these things,” Inagaki said. “It shifts the timing of vaccination and also increases the overall coverage.”
Studies show that HPV vaccines are most effective if provided before people are exposed to HPV through sexual contact, Inagaki said.
Flexibility on timing
Currently, parents and healthcare providers have flexibility about timing HPV vaccinations.The American Academy of Pediatrics and American Cancer Society recommend boys and girls receive the first of two doses of HPV vaccine from ages 9 to 12.
The CDC currently allows kids to be vaccinated as early as 9 years old, but it recommends beginning the two-dose vaccine series at ages 11 or 12, when kids receive two other vaccines and when clinicians address a number of preteen health issues.
Offering HPV vaccines earlier allows children to receive fewer shots in one visit, O’Leary said.
And children in the study who were vaccinated against HPV at younger ages were just as likely as older children to receive other childhood immunizations on time, O’Leary said.
Questions about length of efficacy
Children vaccinated against HPV at age 9 show a robust immune response that lasts at least 15 years, O’Leary said. The HPV shot has been available for just 20 years, so the data on long-term efficacy are limited.But studies show that HPV vaccination spurs the body to produce a lot of antibodies against the virus right away, O’Leary said. As time goes by, the number of antibodies falls but remains high.
“The hope is that the vaccine efficacy will last for a long period of time, potentially covering adulthood, but we don’t yet have data to support that,” Inagaki said.
Some parents have been reluctant to vaccinate their children against HPV, because they don’t want to appear to condone premarital sex. There’s no evidence, however, that people vaccinated against HPV become sexually active at earlier ages. In fact, sexual activity among teens has decreased since the vaccine was released.
“Early vaccination may more effectively frame HPV vaccine as cancer prevention, not necessarily a conversation about sexuality,” O’Leary said.