Is the Human Papillomavirus (HPV) vaccine more effective when administered to young individuals?

From the Guidelines

Yes, the HPV vaccine is more effective when received at a younger age, ideally between 11-12 years old, before potential exposure to the virus through sexual activity. The vaccine, available as Gardasil 9 in the US, protects against HPV types that cause most cervical cancers and genital warts.

Key Points

• The standard regimen is two doses given 6-12 months apart for those who start vaccination before age 15, while those starting at age 15 or older need three doses (0,1-2, and 6 months) 1.
• The vaccine produces a stronger immune response in younger individuals, with studies showing nearly 100% protection against targeted HPV types when given before sexual debut 1.
• This stronger immune response in younger recipients creates higher antibody levels that provide longer-lasting protection.
• While vaccination is still beneficial for older individuals up to age 45, its effectiveness decreases if the person has already been exposed to HPV strains.
• The vaccine cannot treat existing HPV infections, which is why early administration before potential exposure is optimal for maximum protection.

Recommendations

• Girls 11 to 12 years of age should be immunized routinely with 3 doses of quadrivalent HPV vaccine administered intramuscularly at 0,2, and 6 months 1.
• All girls and women 13 through 26 years of age who have not been immunized previously or who have not completed the full vaccine series should receive quadrivalent HPV vaccine 1.
• HPV vaccine can be administered at the same visit as all other recommended vaccines 1. The rationale for routine immunization at 11 to 12 years of age is that, to be most effective, the vaccine should be given before a female becomes sexually active, as supported by studies showing the vaccine's effectiveness in preventing infection with the 4 types of HPV included in it 1.

From the FDA Drug Label

The primary analyses were conducted in the per-protocol population, which included subjects who received all three vaccinations within one year of enrollment, did not have major deviations from the study protocol, and were HPV-naïve Anti-HPV 6,11,16 and 18 GMTs at Month 7 for GARDASIL 9 among girls 9 through 15 years of age and young women 16 through 26 years of age were non-inferior to those among the corresponding populations for GARDASIL Anti-HPV GMTs at Month 7 among 9- through 15-year-old girls and boys were non-inferior to anti-HPV GMTs among 16- through 26-year-old girls and women

• Key Findings:
  • The HPV vaccine (GARDASIL 9) was found to be non-inferior in terms of immune response (as measured by Geometric Mean Titer (GMT)) in 9- through 15-year-old girls and boys compared to 16- through 26-year-old girls and women.
  • The immune response to the vaccine was similar or higher in younger individuals (9- through 15-year-old girls and boys) compared to older individuals (16- through 26-year-old girls and women) for some HPV types.
• Conclusion: The HPV vaccine is at least as effective in younger individuals (9- through 15-year-old girls and boys) as it is in older individuals (16- through 26-year-old girls and women), and may be more effective for some HPV types in younger individuals 2.

From the Research

Effectiveness of HPV Vaccine by Age

• The HPV vaccine is most effective when administered at younger ages, with vaccine effectiveness estimates ranging from approximately 74% to 93% for adolescents ages 9-14 years 3.
• Studies have shown that the vaccine's effectiveness decreases with increasing age, with estimates ranging from 12% to 90% for adolescents ages 15-18 years 3.
• The ideal age for HPV vaccination is 11 or 12 years old, regardless of the patient's sex, with a two-dose series recommended if administered before 15 years of age 4.

Importance of Early Vaccination

• HPV vaccination before sexual debut can prevent HPV infections, precancers, and cancers, making it a crucial strategy for cervical cancer prevention 5.
• Vaccination at a young age can prevent future infections and related cervical abnormalities, but it does not treat pre-existing HPV infections 6.
• The introduction of HPV vaccines can also prevent other HPV-related sequelae, such as cervical intraepithelial neoplasia grade 2 or 3 (CIN2/3), which precede the development of cervical cancer and require clinical follow-up and treatment 6.

Real-World Effectiveness of HPV Vaccines

• A population-based matched case-control study aims to estimate the effectiveness of HPV vaccines in real-world clinical settings and determine how the vaccine's effectiveness varies based on age at the time of immunization and the number of doses received 7.
• The study will investigate the effectiveness of HPV vaccines in preventing high-grade cervical lesions (HGCLs) associated with HPV types 16 and 18, and will control for potential confounders using multivariate conditional logistic regression 7.