A decade ago, a London cancer prevention researcher predicted that the United Kingdom’s national HPV vaccination campaign would take more than 15 years to prevent a majority of cervical cancers. So when he analyzed the data this year, he was stunned to find that the vaccine may already have nearly eliminated cervical cancer in the U.K. among young women.
“If this is right,” Peter Sasieni of King’s College London said of his findings, cervical cancers “could be reduced to about 50 – just 50 cancers in the whole of the U.K. for women under 30. It’s really quite exciting to see that day come – excitement and just joy.”
That joy was tempered with envy in the United States, where some of Sasieni’s peers lamented that the HPV vaccination rate for teenage girls lags far behind — about 59% in the U.S. vs. more than 85% in the U.K. The analysis, published last week in the Lancet, suggests the U.K. has notched a major public health victory against cancer through vaccinating the vast majority of young women against HPV, said Allison Kempe, a pediatrics professor at the University of Colorado School of Medicine who did not work on the study.
“It’s very strong and fairly direct data” that the vaccine reduces cancer, she said. “It’s an incredible achievement to have, first of all, got rates that high among girls 12 to 13 years old. You can see the amazing results of that, almost eliminating a very common and invasive cancer,” she said. “And I’m very, very disturbed that we can’t do better in this country.”
Certain strains of HPV, or human papillomavirus, can cause cellular abnormalities. Those anomalies can develop into six different kinds of cancer, all genital in nature except throat cancers, but it’s most known for its association with cervical cancer. When the Food and Drug Administration first approved an HPV vaccine in 2006, health experts hailed the decision as a major breakthrough for women’s health. It was the first vaccine that could prevent this common and invasive cancer that kills thousands of women in the U.S. each year, and epidemiologists looked ahead with the hope that, one day, widespread vaccinations would trample HPV-related cancers into the past.
Some countries, it appears, are on their way to achieving that. The U.K. implemented its national vaccine program for HPV in 2008, offering two doses of the shot in schools to every adolescent girl. At over 85%, the acceptance rate for the immunization is sky-high there. To understand the effect of that on cervical cancer in his study, Sasieni and his colleagues compared women in the U.K. who were offered the vaccine in school as teens and preteens against slightly older women who were not offered the shot, all under the age of 30.
The team found that women who were offered the vaccine at ages 12 to 13 had an 87% lower risk of cervical cancer than those who were not offered the vaccine at the same age. Their risk of an abnormal Pap smear, a screening test that detects signs of potential cervical cancer, was lower by 97%. That means, Sasieni said, cervical cancer “becomes a very rare cancer, instead of what was one of the most common cancers in young women.”
Based on their findings, Sasieni extrapolated that the vaccination will drive cervical cancer cases down to 50 per year among women under 30 in the U.K. from more than 400 per year before HPV vaccination.
In the U.S., the HPV vaccine has not had such success. Instead, it’s had to slog through a quagmire of social and economic objections since the day it was approved. Some pointed out that the shot was just plain expensive, making it hard for states to justify school vaccine mandates, but the greatest opposition to the vaccine has come because it became entwined with the subject of teen sex. Some advocacy groups opposed mandating HPV vaccines since HPV can be transmitted sexually, arguing instead that public health efforts be focused on keeping kids from having sex.
“I think the biggest mistake was the way this vaccine was introduced into this country,” Kempe said. “There was a lot of discussion about sexual activity. The focus was on sexual activity and getting it into early adolescents before sexual activity. That was a big mistake. Parents got concerned that this meant their child was sexually active or it would trigger sexual activity.”
Kempe said that led the vaccine to be treated differently than other cancer-preventing vaccines, like the hepatitis B vaccine. From the start, Kempe said doctors and scientists should have focused on the fact that the HPV vaccine is a cancer-prevention vaccine, not one that stops a sexually transmitted infection.
“It doesn’t even take sexual intercourse to transmit HPV,” Kempe said. “Heavy petting can do it. Parents might think, ‘My child is not having sexual intercourse so therefore, they don’t need this vaccine.’ That’s a fallacy.”
Today, the whiff of sexual activity still lingers around the vaccine, leading parents to continue to refuse the shots for their kids or — in some cases — halt research on the immunization. Eric Adjei Boakye, a cancer epidemiologist now at Southern Illinois University, once tried to initiate a study of the vaccine at a Roman Catholic university.
“The school said, ‘No! You can’t do that,’” he recalled. “So, the study never happened. They did not want to associate the school at all with the HPV vaccine. So, religion plays a really big role in hesitancy.”
But things haven’t all been bad, Adjei Boakye said. The vaccination rate for HPV has climbed steadily over the years and about 75% of adolescents get at least one shot, which might provide ample protection for at least several years, he pointed out. And cervical cancer screening has also helped to catch and freeze cancers before they can start. Today, there are about 14,000 new cases of cervical cancer diagnosed in the U.S. each year.
“It used to be really high, like 40,000,” Adjei Boakye said. “Now it’s become really small.”
That said, there are five other cancers that HPV causes: penile, vaginal, vulval, anal, and head and throat cancers. It’s much harder to screen for those cancers, and there are still about 45,000 cases overall of HPV-associated cancers diagnosed each year. And, Adjei Boakye said, most of those are probably preventable simply by giving a very safe and effective shot.
The University of Colorado’s Kempe said that might be done better by employing a few hesitancy-fighting strategies like getting buy-in from trusted community leaders and, importantly, finding the right ways to communicate public health messages. Kempe said that might not only help push up rates of the HPV vaccine but also the Covid-19 vaccine.
“We need to use the right words,” Kempe said. “Just spouting facts at people tends not to work.”
Correction: A previous version of this story incorrectly stated the number of new cervical cancer cases diagnosed in the U.S. each year.
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