HPV Vaccine Before 23 Protects Gay Men From Anal HPV

A large Canadian study of 1,519 gay, bisexual and other men who have sex with men has found that the HPV vaccine sharply lowers the risk of anal infection with cancer-linked virus types, but only when the shots come early. The research was published in the Journal of Infectious Diseases in August 2026 and tracked men living in Montreal, Toronto and Vancouver from 2019 to 2021. The strongest protection appeared in participants who were vaccinated by the age of 23. The finding matters because high-risk types of human papillomavirus cause more than 90 percent of anal cancers, a disease that most commonly affects gay, bisexual and other men who have sex with men, according to a summary from the University of British Columbia's Advancing Health centre.

The details make the case for early vaccination hard to ignore. Among 16- to 26-year-olds in the study, 62 percent had received the HPV vaccine, compared with 40 percent of 27- to 45-year-olds and just 15 percent of men 46 and older. The clearest benefit showed up in participants who had received their first dose at least three years earlier and had five or fewer years of sexual activity before being vaccinated. The protection held regardless of HIV status. In the older age groups, vaccinated men also carried fewer vaccine-preventable anal HPV types, but the difference was smaller.

Timing is the whole story

The reason timing matters is straightforward biology. The HPV vaccine prevents new infections but cannot clear an infection someone already has, and people can encounter the virus before they realize they have been exposed. Giving the immune system a head start is the point. That is why the American Academy of Pediatrics recommends routine HPV vaccination starting between ages 9 and 12, years before sexual activity is likely, and why researchers keep framing the shot as cancer prevention rather than a response to risk. Medical Daily made the same point in its coverage, noting that vaccination before exposure gives the immune system its chance to build protection in advance.

A wider evidence base for men

The Canadian study is not the only recent signal. Medical Daily reported on a randomized trial in Japan that followed more than a thousand men given the nine-valent HPV vaccine or a placebo, and found the vaccine prevented 92 percent of persistent infections with the types it targets, while also reducing persistent infections from other types. A separate review spanning 21 studies published between 2007 and 2024 linked vaccination to lower rates of anal, penile and oral HPV infections in men. A separate observational study of more than one million males tied vaccination to a nearly 50 percent lower risk of HPV-related cancers, although its authors cautioned that the design could not prove cause and effect.

There is still a gap between these findings and the biggest question, which is how many cancers the HPV vaccine actually prevents in men. The recent studies measured infection, especially persistent infection, not decades of cancer outcomes, and HPV-related cancers can develop many years after exposure. Long-term follow-up will be needed to measure the full effect. The case for acting now rests partly on what cannot be screened: unlike cervical cancer, HPV-related throat cancer has no routine early-detection program, so preventing the infection carries the heavier load.

For now, the practical message is simple. Health authorities already recommend the HPV vaccine for all adolescents, and the new data sharpen the advice for gay and bisexual young men in particular: the earlier the series starts, the stronger the shield. Adults who missed the window can still ask a clinician about catch-up vaccination, which can guard against virus types they have not yet encountered. Nobody in the study was followed long enough to count cancers averted, but every new analysis points the same way, and the clock starts earlier than most people assume. What the data do not show is that later vaccination is useless, only that the benefit shrinks, which is why catch-up doses still earn a recommendation for adults who missed the earlier window.