Dalla Lana School of Public Health

Addressing Barriers to Cancer Preventing Care: The importance of HPV and HBV childhood vaccinations

June 4/2026

Experts from DLSPH’s Centre for Vaccine Preventable Diseases (CVPD) speak on the importance of HPV and HBV childhood vaccination for cancer prevention. 

By Aislinn DeRoches

A recent study from the World Health Organization (WHO) found that of the 18.7 million cancer cases in 2022, 7.1 million of them were caused by preventable factors — including infectious diseases. Of those, human papillomavirus (HPV) was one of the most prevalent causes of cancer — resulting in approximately 4.5 per cent of cancers globally, including cervical, anal, oropharyngeal, penile, vaginal, and vulvar cancer. Hepatitis B virus (HBV), another infectious disease, was also found to be a major cause of cancers like liver cancer.

The good news is, both HPV and HBV infections are preventable by vaccination.

“Fortunately, vaccination offers a high level of protection against these risks,” says Tara Martin, a Research Analyst (Epidemiologist) at the Centre for Vaccine Preventable Diseases (CVPD) at the Dalla Lana School of Public Health (DLSPH). “The 9-valent HPV vaccine is approximately 95 to 100 per cent effective at preventing infection and precancerous disease caused by the HPV types it targets. Similarly, the HBV vaccine is 96 to 100 per cent effective at preventing chronic hepatitis B infection, with protection lasting for decades.”

Vaccine coverage goals and where Canada stands

Despite publicly funded school vaccination programs for both HPV and HBV being offered in every province and territory, with some provinces also offering infant immunization against HBV, Canada remains below its national vaccine coverage goal of 90 per cent.

A recent study conducted at the CVPD by Martin, DLSPH Assistant Professor Ramandip Grewal, Assistant Professor Gilla Shapiro, and colleagues, Sociodemographic correlates of human papillomavirus and hepatitis B vaccination status in Canada: a cross-sectional study, examined the Childhood National Immunization Coverage Survey (cNICS) data from 2021 and found that the one-dose uptake of the HPV and HBV vaccines in Canadian 14-year-olds was 74.9 per cent and 78.7 per cent, respectively.

The study also found a close association between certain sociodemographic factors and unvaccinated children or children with an unknown vaccination status — thus identifying potential barriers to vaccination.

The barriers to HPV and HBV vaccination in children

According to their study, approximately 11 per cent of parents did not know if their child had received an HPV or HBV vaccine— a finding that not only raises concerns in terms of parents’ awareness of their children’s vaccination status but also presents issues when it comes time to estimate vaccine coverage, says Martin.

“Excluding [individuals with an unknown vaccination status] may overestimate vaccine coverage, while classifying all unknowns as unvaccinated can introduce misclassification bias,” explains Martin. “Without a comprehensive immunization registry data, it is difficult to accurately assess true vaccine uptake.”

The study found that 14.3 per cent of 14-year-old children were unvaccinated against HPV and 10.9 per cent had an unknown vaccination status. Of the 14.3 per cent of children who were unvaccinated against HPV, higher proportions were observed among those whose parents had a high school education as their highest level of education (17.5 per cent), Indigenous children (16.7 per cent), boys (15.9 per cent) and children living in rural areas (15.9 per cent).

Among the 10.9 per cent with an unknown HPV vaccination status, the highest proportions were observed among Indigenous children (27.5 per cent), children with parents between the ages of 15 and 39 years old (15.9 per cent), and children with parents who were never married or were separated, divorced, or widowed (15.6 per cent).

For HBV vaccination, 9.8 per cent of children were unvaccinated and 11.6 per cent had an unknown vaccination status. The highest proportions of unvaccinated children were observed among those whose parents had a high school education or less (18 per cent), those living in Ontario (13 per cent), and those living in rural areas (12.2 per cent). Indigenous children had the highest proportion of unknown vaccination status (21.9 per cent).

“To decrease inequalities in vaccine uptake, we need to tailor strategies to reach these populations,” explains Dr. Grewal, who is a CVPD member. “Some of this may include more effective messaging, one example being reducing complexity in consent letters.”

Boys vs. Girls— the role of gender in vaccination status

There also appears to be a noticeable differences in vaccination status  between boys and girls.

According to the study, first-dose receipt of both HPV and HBV vaccines was higher for girls than boys, and parents of boys were half as likely to know their son’s HPV vaccination status compared to parents of girls.

“HPV affects all people. Vaccinating all children contributes to population-level protection,” says Dr. Shapiro, CVPD member and Psychologist and Clinician Scientist at the Princess Margaret Cancer Centre. “Clear, consistent messaging to parents, school-based reminders, and provider-led recommendations that explicitly include boys are some of the strategies that are effective in increasing vaccine uptake.”

This finding highlights the need to evaluate the approach to school-aged children vaccination programs to see where there is room for growth and identify who is being left behind.

“We need to think about how we can improve accessibility to the vaccine if the first vaccination opportunity is missed,” says Dr. Grewal. “Essentially, we really need to start thinking about the bigger picture.”

How a national vaccine registry could help HPV and HBV immunization programs

When looking at Canada’s HPV and HBV vaccine coverage, the question of “what can be done?” often centres on the choices of parents and individuals — but changes need to be made at a macro level as well.

A national vaccine registry, in addition to more provincial registries, could be greatly beneficial by allowing health professionals to easily and accurately document and access people’s vaccination records across provinces, territories, and regions.

“A national vaccine registry would help us better understand who is not getting vaccinated against HPV and HBV, which can help inform strategies to address relevant barriers and increase vaccine uptake,” says Dr. Grewal. “This will also help us understand how successful vaccination has been across Canada and look at the impact from a national perspective.”

The importance of HPV and HBV immunization and the need for improved vaccine surveillance

This research is critical in the pursuit of increasing vaccine uptake in Canada, as it identifies the existing barriers to HPV and HBV vaccination, highlights parental awareness gaps regarding their children’s immunization status, and reinforces the benefit that a national vaccine registry could have in addressing vaccine coverage gaps.

Dr. Shapiro further emphasizes the importance of equitable opportunities for HPV and HBV vaccinations in order to protect children from preventable cancer risks, stating that vaccinating children is “a proactive step” to protect a child’s health in the long run.

“HPV and HBV vaccination are among the most effective tools we have to prevent cancer at a population level,” she says. “Closing gaps in access, providing clear and consistent messaging, and strengthening public trust are essential to effective cancer prevention.”