It wouldn’t be an overstatement to call the HPV vaccine a medical miracle.
“It’s like the gift that keeps giving,” says Mark Jit, a professor of vaccine epidemiology at the London School of Hygiene & Tropical Medicine. Not only is it the sole vaccine that can prevent cancer, “we discover it’s an even better vaccine as time goes on,” he says.
Since its development and rollout in the mid-2010s, the HPV vaccine’s prowess at heeding off cervical cancer rates has been remarkable. Over an 11-year period in the United Kingdom, cases of cervical cancer fell by 87 percent among those who received the vaccine compared to those who didn’t. It’s conceivable that one day, a whole form of cancer could be effectively eliminated.
And the vaccines don’t just protect against cervical cancer. They can also prevent head and neck, vaginal, anal, and penile cancer, as well as protecting against genital warts in both genders. But there’s the rub: Although these vaccines protect against cancers that affect both men and women, boys and men aren’t offered the vaccine in two-thirds of countries where they are available. In those places, half the people who could benefit are missing out on a potentially life-saving intervention. But that’s starting to change.
When the rollout of HPV vaccines was first gearing up—and their price was still high—it made sense to target the most at-risk group, says Jit, that being girls between the ages of 9 and 14. But in the intervening decade or so, the vaccines have dropped significantly in price. Over the same period, research showcasing the benefits of gender-neutral HPV vaccine campaigns has compounded. “From a social justice and equality point of view, it makes sense to vaccinate men and women,” says Kit Yates, a mathematical biologist at the University of Bath. Failure to do so means men are left at risk, and this places the onus on women to protect men from HPV, rather than sharing the burden.
A barrier to wider rollout in recent years has been uneven supply: as eligible groups expanded, demand shot up. The makers of the vaccines couldn’t keep up, and there was a major squeeze, meaning many low-income countries had to go without. But supply has started to ramp up again, and India—the world’s largest vaccine producer—debuted its own home-grown vaccine last year.
New research has also shown that just one dose offers sufficient protection, meaning the usual two-dose regime can be halved and double the people can be included in national rollouts. “Now is the time we can start asking, actually, are there other groups that should be vaccinated?” says Jit.
HPV, or human papillomavirus, is the everyman STI. Between 80 and 90 percent of people will acquire it at some point in their lives, typically through skin-to-skin contact. Odds are that you, reader, will probably pick up the virus—if you haven’t already. Luckily, for most carriers it won’t have an impact; you can be asymptomatic for your whole life.
But for a small chunk of carriers, HPV can lead to potentially fatal cases of cancer; of the around 200 types of HPV, scores are cancer-causing. HPV becomes cancerous by sneaking into the body and burrowing itself into cells, where it photocopies itself. Most infections won’t take root, and your body will boot them out within a year or two. But some persistent infections can linger on, changing normal cells to abnormal cells, which can lead to cancer if untreated.
It’s estimated that nearly 700,000 people are diagnosed with HPV-related cancer around the world each year. The majority of those cases will be cervical cancer, which causes an estimated 340,000 deaths annually, the fourth most common cancer among women, for which HPV causes almost all cases. But more than a quarter of cancer cases linked to HPV are in men.
Historically, an HPV infection has been seen as a “female problem”—what scholars have dubbed the “feminization of HPV.” This, it’s been argued, further entrenches the idea that women are “responsible for reproductive health care in heterosexual partnerships,” as well as stigmatizing women for carrying and infecting men with HPV. The initial clinical trials for the vaccines only included women, and the subsequent marketing targeted only mothers and young women.
But a recent paper in The Lancet analyzed existing research to ballpark how common genital HPV infections are among men—a statistic well researched in women but much less understood among their male counterparts. The researchers found that almost one in three men are walking around with an HPV infection. They also concluded that men are a reservoir for HPV, meaning that it poses a risk not only to them, but to those who have sex with them.
And cancers that appear more often in men are spotted less often. Unlike pap smear campaigns for women that catch cervical cancer, no such regular screening test exists for penile, head and neck, or anal cancer. These cancers are a growing problem. The rise in throat cancer in recent decades (because people are giving more oral sex) has been called an epidemic. In the US, the number of cases of head and neck cancers caused by HPV has now overtaken cervical cancer as the most common HPV-related cancer.
The economic argument behind only vaccinating girls against HPV has rested on the idea that men will benefit by proxy through herd immunity. But that only makes sense from a heteronormative perspective; men who have sex with men stand to benefit a lot less from female-only vaccine campaigns, and this group has already been shown to be more at risk of contracting an HPV infection. Yes, vaccinating women will also lead to a reduction in HPV infections in men—but actually, “that benefit is sort of overstated if you only include heterosexual relationships, which some of the early models did,” says Yates.
Global health agencies are still espousing the women-only message. The World Health Organization’s recommendation for HPV vaccination scheduling suggests a primary target of over 90 percent of girls getting the vaccine before they turn 15. This, the WHO says, is because in low- and middle-income countries, a female-focused vaccination campaign remains the most cost-effective.
But some countries have heeded the research and begun to include boys in their vaccination drives. Australia became the first country to include boys in 2013, and other countries have followed suit, including the UK, New Zealand, Argentina, Ireland, and Canada.
But who is included in the rollout of HPV vaccines is only part of the problem. HPV vaccine uptake has been curtailed by a culture of mistrust and hesitancy. Despite years of data showing the vaccines to be safe, fear of side effects is a common reason behind low uptake rates. A 2021 paper found that between 2015 and 2018, the amount of parents choosing not to get their kids vaccinated due to safety concerns rose by nearly 80 percent in the US.
And even among parents who aren’t vaccine-hesitant, there’s a persisting resistance to vaccinate their children owing to a fear that it will make their kids sexually active, since they now have a “safety net.” HPV vaccines work best when they’re administered before an individual becomes sexually active, so campaigns typically target 11- to 12-year-olds. (Research has shown that receiving the vaccine does not make teens more likely to partake in sexual activity.) Another 2021 study found that globally only 15 percent of girls in the target age range for the vaccines have been fully protected; that number drops to just 4 percent for boys.
The global rollout is far from even. While progress in countries such as the US and UK has stalled, coverage is continuing to increase in lower-income countries—but overall progress towards the WHO’s primary goal of vaccinating 90 percent of eligible girls is slow. Jit, though, thinks the WHO should hold even loftier plans long-term. He and his colleagues have argued that we should take the same approach as the world did with smallpox, the only human disease to have been eradicated. The idea was that if enough people were vaccinated against the virus, it would eventually cease to exist, which officially happened in 1980 after intense mass vaccination efforts.
“Maybe that should be our end goal, not to say, let’s keep vaccinating people forever,” he says. “But let’s get to the point where we never have to vaccinate again, because the virus doesn’t exist anymore.”
