U of T research extends real-world evidence on HPV vaccine to a group largely left out of it so far: older gay, bisexual, and other men who have sex with men living with HIV
September 29/2026
This story was originally published by the Emerging Pathogens & Infectious Diseases Consortium (EPIC).
By Megan Fleming
When most people hear “human papillomavirus (HPV) vaccine,” they picture school clinics, teenage girls and cervical cancer prevention. Pranamika Khayargoli, a 2025 Emerging Pathogens & Infectious Diseases Consortium (EPIC) Doctoral Award recipient and PhD candidate in epidemiology at U of T’s Dalla Lana School of Public Health, remembers having the same assumption until her graduate research introduced her to a population less often included in HPV studies: men.
“I didn’t even know men could get HPV,” Khayargoli says. “You hear about HPV, you hear about cervical cancer. So then when I found out, wait, men can also get HPV and HPV-associated cancers, I got really interested.”
This gender gap and the body of research showing that men who have sex with men living with HIV face a much higher risk of anal cancer set Khayargoli on the path to her latest study, published in summer 2026 in The Journal of Infectious Diseases.
The study draws on Canada’s Engage Cohort Study, which includes participants recruited from 2017 to 2019 and has already produced several rounds of real-world evidence that the HPV vaccine works in men. The novelty that Khayargoli’s research adds is that it is the first to report any vaccine effectiveness data in men over 45, extending the evidence base to an older age group, and a population living with HIV, that earlier real-world studies largely didn’t capture.
Vaccinated early, protected: what the study found in younger men
Khayargoli and her co-authors worked with data from the Engage-HPV study, a nested study within the Engage Cohort Study, which followed gay, bisexual and other men who have sex with men (GBM) in Montreal, Toronto and Vancouver for over six years. They looked at more than 1,100 participants aged 18 to 83 to see how anal HPV prevalence differed between vaccinated and unvaccinated men in the years just after male HPV vaccination programs for GBM launched in Quebec, Ontario and British Columbia.
“Something we can say confidently, and something we did expect, is that there was lower HPV prevalence among those vaccinated at younger ages, as well as those with fewer years of sexual activity [before vaccination],” Khayargoli says.
85 per cent unvaccinated: older men living with HIV previously left behind
More than 85 per cent of the oldest men, aged 46 years and above, in the study had never been vaccinated. This number didn’t completely surprise Khayargoli, since male HPV vaccination programs simply didn’t exist when they were young. But the scale of it did.
“I was still shocked to see it was over 85 per cent, especially when I’m looking at all these anal cancer studies where we see higher risk among older men. We need to do something about this.”
Through a community advisory board of GBM of diverse ages and lived experiences from Montreal, Toronto, and Vancouver, Khayargoli’s team heard directly from older men living with HIV about why they hadn’t been vaccinated yet. Some assumed the vaccine was “for females only.” Others knew about their cancer risk but couldn’t justify the cost, as out-of-pocket doses can run up to $200 each.
Khayargoli was careful about the variables she used to explore this. Rather than relying on age alone, the study also tracked years of sexual activity before vaccination.
“It’s really supposed to be a proxy for sexual exposure, because that’s how you transmit HPV,” she says. “You don’t necessarily just get more sexually active with age,” so age by itself can be misleading, especially given persistent and unsupported assumptions that vaccinating younger people encourages promiscuity.
What’s next? Tracking infections over time and exploring novel cancer biomarkers
This is the first of three papers from Khayargoli’s PhD work, and she’s already looking past prevalence, which covers only a single snapshot in time, toward outcomes that track how infections behave over years: new infections (incidence) and infections that don’t clear on their own (persistence), which is a closer proxy for cancer risk.
She’s also co-written a grant that was successfully funded by the Cancer Research Society with her supervisor, Ann Burchell, a professor in the department of family and community medicine at the U of T’s Temerty Faculty of Medicine and a scientist at the MAP Centre for Urban Health Solutions at Unity Health Toronto, to test stored HPV specimens for novel biomarkers linked to HPV-associated anal cancer in collaboration with researchers at McGill University.
Asked for one takeaway, Khayargoli offers two: HPV vaccination works for GBM too, and it works best when given early, before sexual debut, just as it does for women. But older men living with HIV remain an important, unprotected group when it comes to preventing HPV-associated cancers.
“This paper is one of the first to report any vaccine effectiveness data in men over 45 years,” she says. “We were underpowered to draw strong conclusions in these older men, but I think it’s still good to highlight how important it is that this research captures men across the whole life course.”
The power of community-based research and connection
Khayargoli credits her time at U of T, and Burchell’s mentorship, with teaching her community-based research methods she’d never used before, including how to bring findings back to the people the research is about in a compassionate and meaningful manner.
“It becomes so much more than just data. Each data point represents real people,” she says. One member of the Engage-HPV study’s community advisory board is also a study participant himself. “It’s a great two-way collaboration… and honestly, very humbling.”
Research on HPV vaccination in males hasn’t always attracted funding or attention, which is part of why Khayargoli says the EPIC Doctoral Award arrived at a pivotal moment in her training. The award also came with its own push for Khayargoli to communicate her research beyond her field. She was invited to give a five-minute talk at the 2025 EPIC Symposium, explaining her research to non-specialists. The recognition further motivated her to continue applying, and she subsequently received the Doctoral Research Award, a graduate studentship from the Canadian Institutes of Health Research.
“I didn’t get any of the other awards I applied for,” she says. “Getting the EPIC funding was the boost I needed. It made me feel like my research does matter.”