Human papillomavirus vaccine for children and adolescents

Question 1

Which genotypes are associated with cancer?

Answer 1

HPV-16 and HPV-18 70% squamous cell carcinoma and 86% of adenocarcinomas of the cervix

Also associated with penile, anus, vulva, and vaginal, conjunctival, mouth, oropharynx, tonsils, and larynx cancers

HPV-31, -33, -35, -45, -52, -58 –> 20% cervical cancers

Question 2

Which genotypes are responsible for genital warts and recurrent respiratory papillomatosis?

Answer 2

HPV-6 and HPV-11 90% of genital warts

Question 3

What is the overall prevalence of HPV in Canada?

Answer 3

11-29%

Question 4

What are risk factors for HPV infection?

Answer 4

1. <20yo
2. Inuit women
3. Number of sexual partners
4. Early age of first intercourse
5. Never being married
6. Never being pregnant
7. Immunosuppression

Question 5

What percentage of grade 6 children have had their first sexual intercourse?

Answer 5

1-4%

Question 6

What percentage of grade 7 children have had their first sexual intercourse?

Answer 6

3-4%

Question 7

What percentage of grade 9 children have had their first sexual intercourse?

Answer 7

17-23%

Question 8

What percentage of youth have had their first sexual intercourse by grade 11 or by 16yo?

Answer 8

40-46%

Question 9

What does Gardasil cover?

Answer 9

Quadrivalent vaccine against HPV-6, -11, -16, -18 genotypes

Question 10

What is the efficacy of the vaccine?

Answer 10

95.6% effective against HPV 16 and 18
98% effective against prevention of dyplastic lesions
100% effective against high grade vaginal and vulvar lesions
99% effective against genital warts

In general population 16-26yo: 44-55% against HPV 16 and 18 pre-dysplastic cervical lesions

Question 11

What is the vaccine schedule?

Answer 11

Give 0.5mL IM at 0, 2, and 6 months

Question 12

What are the CPS recommendations regarding HPV vaccine?

Answer 12

1. HPV vaccine should be administered routinely to all girls between nine and 13 years of age. To increase the likelihood that the vaccine will be administered before the onset of any sexual activity (therefore providing optimal protection against initial infection with the HPV vaccine genotypes), the vaccine should be given as early as programmatic issues allow.
2. Given that street-involved children and youth, as well as those taken into care by authorities (ie, foster care, group homes) are at higher risk of early onset of sexual activity, increased numbers of sexual partners and STIs as well as being at greater risk of missing immunization opportunities, specific attention should be paid to immunizing this population of girls.
3. The vaccine should be administered to all unimmunized females 13 years of age and older, for whom the vaccine is approved, as a ‘catch up program’.
4. Females who have had previous Pap abnormalities (including cervical cancer), genital warts or known HPV infection should also be offered HPV vaccination because they may not have had infection with all of the HPV genotypes included in the vaccine and may still benefit from its administration.
5. Physicians caring for children and youth must continue to advise that immunized girls take part in the currently recommended cervical cancer screening programs once they are sexually active.
6. Education programs explaining behaviours that can reduce the acquisition of nonvaccine HPV genotypes and other STIs must continue for all children and adolescents who are sexually active, regardless of their HPV immunization status. These behaviours include consistent condom use and limiting the number of sexual partners, neither of which are completely effective against acquisition of HPV infection.
7. While the efficacy of the HPV vaccine has not yet been demonstrated in males and, therefore, cannot be recommended at this time, immunological data are convincing and efficacy studies should be addressed as an urgent research priority. Some countries have already initiated immunization programs for boys.
8. While data regarding the immunogenicity and efficacy of HPV vaccine in immunocompromised individuals are currently lacking, such individuals may be offered the vaccine based on expert opinion. The dose and schedule should be in accordance with recommendations for the nonimmunocompromised population.
9. There are several urgent research priorities that should be addressed regarding HPV vaccine. These include but are not limited to:
   a) Enhanced Canadian epidemiological knowledge of HPV infection and disease across the age spectrum in both males and females;
   b) Vaccine efficacy in males;
   c) Vaccine safety and efficacy in immunocompromised individuals;
   d) Long-term outcomes following HPV immunization;
   e) Cost-effectiveness studies that are independent of industry; and
   f) Optimal and alternate vaccine dosing schedules.
10. Physicians caring for female children and youth should counsel patients and their parents about the HPV vaccine, making it available even in the absence of a provincially or territorially funded universal program.
11. Physicians caring for children and youth should advocate for and support the funding and implementation of universal HPV vaccination programs within all provinces and territories.