NACI Updated recommendations on human papillomavirus vaccines

Globally and in Canada, human papillomavirus (HPV)-associated diseases are a significant public health problem. Human papillomavirus (HPV) infection is very common in Canada. Without vaccination, it is estimated that 75% of people will have at least one HPV infection in their lifetime. HPV-associated diseases include anogenital cancers such as cervical cancer and anal cancer, as well as oropharyngeal cancer.

HPV vaccination, along with surveillance and screening strategies, are core public health measures for the prevention of HPV-associated cancers. The current goal of the Canadian HPV Immunization program is to reduce vaccine preventable HPV-related morbidity and mortality in the Canadian populationFootnote1. Additionally, the Canadian Strategy for Cancer Control calls for the elimination of cancers caused by HPV through universal access to HPV vaccine programs for all children, delivered in a culturally sensitive wayFootnote2. As part of Canada's commitment to the country's action plan, which aligns with the World Health Organization's (WHO) cervical cancer elimination initiative, Canada has set a national target to achieve 90% vaccination coverage for two or more doses of HPV vaccines by 17 years of ageFootnote3. The goal aligns with HPV vaccination goals set forth in the Canadian Partnership Against Cancer Action Plan for the Elimination of Cervical Cancer in CanadaFootnote4.

Rates for completion of a 2-dose HPV vaccine series in the context of school-based immunization programs continue to vary across Canadian provinces and territories. The most recent publication from the Canadian Partnership Against Cancer Action reports HPV vaccination rates varying between 57 to 91%, based on data from the 2017/2018 school yearFootnote4. A more recent report from the Canadian Childhood National Immunization Survey from 2021 indicates approximately 84% of 14-year-olds received 1 or more HPV vaccine dose. While this is an increase from 80% vaccine coverage rates in 2019, HPV vaccine coverage rates continue to fall short of the national goalFootnote5.

NACI last issued an updated recommendation on HPV vaccine schedules in 2017, recommending a 2- or 3-dose schedule for those aged 9 to less than 15 years and a 3-dose schedule for older individuals (e.g., 15 years of age and older) as well as those considered immunocompromised or living with HIV. The 2017 guidance considered available evidence at the time, as well as changes to the authorized usage of HPV vaccine allowing for a 2-dose series.

Since then, numerous trials and studies have reported on the benefit of a 1-dose schedule. In December 2022, the WHO issued updated guidance on HPV vaccine schedules noting a single-dose schedule, referred to as an alternative, off-label single–dose schedule, can provide a comparable efficacy and durability of protection to a 2-dose regimen for individuals aged 9 to 20 years. The WHO now recommends:

• A 1- or 2-dose schedule for girls aged 9 to 14 years
• A 1- or 2- dose schedule for girls and women aged 15 to 20 years
• 2 doses with a 6-month interval for women 21 years of age and olderFootnote6

The WHO also notes that the primary target of vaccination is girls aged 9 to 14 to prevent cervical cancer, however secondary populations such as boys and older females are recommended where feasible and affordableFootnote6.

Given ongoing efforts to improve HPV vaccination coverage and reduce HPV-associated burden of disease among people in Canada, and considering recent updated guidance from the WHO, Canadian provinces and territories requested that NACI update guidance on HPV vaccine schedules. NACI also considered additional program updates including updates to the authorized indication of 9vHPV (nonavalent HPV vaccine Gardasil-9, Merck; expanded authorization now includes males 27 to 45 years of age). Updated NACI guidance on the use of HPV vaccines was discussed at NACI on February 8 and April 17, 2024 and approved on May 27, 2024.