VACCINE RESOURCE COMMITTEE

of the Edmonton Zone Medical Staff Association

View Full List of Vaccine Questions Here

Human Papillomavirus Vaccine Question #2:

Why is the vaccine recommended for adolescents if they are not sexually active?

The vaccine is most effective at providing protection when given before exposure.

The vaccines are most effective if given before a person becomes sexually active because the risk of infection will be lower. The vaccines are also more effective in young teens when their immune system is most responsive to the vaccine. 

Research so far shows that protection can last at least 10 years for HPV vaccines. With longer follow-up of HPV vaccines, we’ll learn more about how long protection lasts and whether booster doses are needed for continued protection. There are currently no recommendations to have a booster.

Without vaccination, it is estimated that 75% of people in Canada will have at least one HPV infection in their lifetime. The highest prevalence is in young adults aged 20 to 24. HPV is responsible for almost 3,800 new cancer cases annually in Canada. HPV-associated cancer risk varies by anatomical region and age. Notably, oropharyngeal, vaginal, vulvar, penile, and anal cancers are more likely to occur at older ages compared to cervical cancer.

In Canada, HPV is responsible for virtually all cervical cancers: 90% are due to all high-risk HPV strains targeted by the 9vHPV (Gardisil-9) vaccine. Approximately 1,550 new cases of cervical cancer and 400 deaths were estimated for Canada for 2023. It is the 14th most common cancer among females and the 4th most common among those aged 15 to 44 years in Canada.

Anogenital warts (AGW) is one of the most common sexually transmitted infections worldwide, with up to 90% of cases caused by HPV strains covered by the 9vHPV vaccine. Higher rates of AGW are consistently observed among males compared to females, peaking at 25 to 29 years for males and 20 to 24 years for females. Data from 2000-2017 in British Columbia showed an overall decline of 56% in AGW rates among both sexes following the introduction of the provincial school-based HPV immunization program.

Vertical transmission of HPV strains covered by the 9vHPV vaccine during vaginal delivery in the presence of active maternal infection can cause Juvenile onset recurrent respiratory papillomatosis (JoRRP). While severe, it is very rare, with an annual incidence of 0.24 cases per 100,000 children 14 years of age and younger.

Sources:

Canadian Cancer Society: Who should be vaccinated for HPV?
Government of Canada: Updated recommendations on human papillomavirus vaccines