Human papillomavirus (HPV) is one of the most common infections in the world, and most people will encounter it at some point in their lives. In Canada, it’s estimated that 75% of sexually active people will get an HPV infection at least once. Many never know they had it because most HPV infections cause no symptoms and clear on their own. But certain “high‑risk” strains of HPV can lead to serious health problems, including cancers of the cervix, anus, penis, vagina, vulva, and even the mouth and throat. In 2023 alone, Canada saw 1,550 new cervical cancer cases and 400 related deaths, and nearly two‑thirds of HPV‑related cancers were non‑cervical, affecting both men and women.
HPV is a very small DNA virus that spreads through intimate skin‑to‑skin contact. There are more than 100 strains, but two of them — HPV‑16 and HPV‑18 — cause the majority of HPV‑related cancers. When these high‑risk strains infect the body, they target the skin cells lining areas like the cervix or throat. Most of the time, the immune system clears the virus. But when the infection persists, HPV can interfere with the body’s natural tumor‑suppressor proteins, allowing abnormal cells to grow. Over many years, this can lead to cancer. This long timeline is why HPV‑related cancers often appear decades after the initial infection.
Certain behaviors and life circumstances can increase the risk of getting HPV or developing complications. Having multiple sexual partners, starting sexual activity at a younger age, or having partners with many past partners all raise the chances of exposure. Smoking has been linked to higher rates of cervical abnormalities, and people with weakened immune systems are more likely to develop persistent infections. Men who have sex with men face significantly higher rates of anal HPV infection, with anal cancer occurring up to 44 times more often in this group compared to the general population.
The good news is that HPV is preventable. The Gardasil 9 vaccine, offered by Toronto Public Health, protects against nine HPV strains responsible for over 70% of cervical cancers and 90% of genital warts. The vaccine is safe, well‑studied, and highly effective — in young women, its protection against targeted HPV types is nearly 100%. In Ontario, the vaccine is free for students in grades 7–12 and for certain high‑risk groups. Even adults up to age 26 can benefit from vaccination, and updated national guidelines now recommend one dose for ages 9–20 and two doses for ages 21–26. Vaccination works best before exposure, but even people who already have HPV can still gain protection against other strains.
As HPV‑related cancers continue to rise, especially cancers of the throat and mouth in men, prevention and education are more important than ever. Regular cervical screening, safer sexual practices, and widespread vaccination can dramatically reduce HPV‑related disease. With strong public‑health programs and growing awareness, Canada is well‑positioned to protect future generations from HPV and the cancers it can cause.
