Can I get the Human Papillomavirus (HPV) vaccine if I am already infected with HPV?

HPV Vaccination in Already-Infected Individuals

Direct Answer

Yes, you should get the HPV vaccine even if you are already infected with HPV, as it will protect you against the other vaccine HPV types you have not yet acquired. 1

Why Vaccination Still Benefits Infected Individuals

The vaccine does not treat existing HPV infections but prevents new infections with other HPV types included in the vaccine. 1 Here's the key reasoning:

• Most sexually active individuals are not infected with all four vaccine HPV types (types 6,11,16, and 18 in the quadrivalent vaccine), so vaccination provides protection against the types not yet acquired 1
• Natural immunity from prior HPV infection does not provide complete protection against reactivation or reinfection by the same HPV genotype 2
• The vaccine cannot alter the outcome of an established HPV infection caused by a vaccine type you already have, but it protects against future infections with other vaccine types 1

Evidence for Post-Infection Vaccination Effectiveness

The benefits of vaccination after infection are substantial:

• 64.9% efficacy in preventing new cervical lesions by any HPV genotype in women who had been treated for cervical lesions 2
• 65% reduction in HPV recurrence at 2 years in women undergoing cervical conization, regardless of genotype 2
• 88.2% post-treatment risk reduction of new lesions following bivalent vaccine immunization in women with surgically treated cervical lesions 2
• Long-term follow-up demonstrated protection even in individuals with current or prior HPV infection after approximately 3 years in catch-up vaccination groups 3

Specific Clinical Scenarios Where Vaccination Is Recommended

Women with Abnormal Pap Tests or Known HPV Infection

• Vaccination is recommended even with equivocal or abnormal Pap test results, as these women are unlikely to be infected with all four vaccine HPV types 1
• Women with positive high-risk HPV tests should still be vaccinated, as the test does not identify specific HPV types and they may not have been infected with any vaccine types 1
• The vaccine will not have therapeutic effect on existing infections or cervical lesions, but will prevent new infections 1

Women with Genital Warts

• Vaccination is recommended for women with a history of genital warts or clinically evident genital warts, as they might not have infection with both HPV 6 and 11 or with HPV 16 or 18 1
• Protection is provided against vaccine types not already acquired 1

Women Undergoing Treatment for Precancerous Lesions

• HPV vaccination is strongly recommended for women undergoing treatment for precancerous cervical lesions 2
• Vaccination should not be delayed in the hope of clearing an infection, as new infections with other HPV types can still occur 2

Who Should Receive the Vaccine

Routine Vaccination

• Routine vaccination is recommended for females aged 11-12 years, but can be started as early as age 9 years 1, 2

Catch-Up Vaccination

• All persons through age 26 years who are not adequately vaccinated should receive catch-up vaccination 2
• Vaccination is recommended for females aged 13-26 years who have not been previously vaccinated or who have not completed the full series 1
• For women aged 27-45 years, shared clinical decision-making should be used regarding HPV vaccination, considering the patient's risk for acquisition of new HPV infection 4

Dosing Schedule

For Those Starting Before Age 15

• A 2-dose schedule with doses at 0 and 6-12 months is recommended 2

For Those Starting at Age 15 or Older

• A 3-dose schedule with doses at 0,1-2, and 6 months is recommended 2
• The minimum interval between first and second doses is 4 weeks, and between second and third doses is 12 weeks 1

Critical Points: No Pre-Vaccination Testing Required

No Pap testing, HPV DNA testing, or HPV antibody testing is needed before vaccination at any age 1, 2 because:

• It is not possible for a clinician to assess the extent to which sexually active persons would benefit from vaccination 1
• The risk for HPV infection continues as long as persons are sexually active 1
• Testing would delay vaccination without providing meaningful clinical benefit 2

Important Caveats

Decreasing Benefit with Age and Sexual Activity

• Overall vaccine effectiveness is lower when administered to sexually active populations and decreases with older age and increasing number of sex partners 1, 2
• However, the majority of females aged 13-26 years will derive at least partial benefit from vaccination 1, 2

Continued Screening Necessity

• HPV vaccination does not replace the need for cervical cancer screening, as the vaccine covers approximately 70% of cervical cancer-causing HPV types 1, 2
• Regular screening should continue according to guidelines 2

Special Populations

• Lactating women can receive HPV vaccine without restrictions 1
• Immunocompromised persons can receive the vaccine (it is non-infectious), though immune response may be reduced 1
• Vaccination during pregnancy should be delayed until after completion of pregnancy, though if a dose was inadvertently given, no intervention is needed 1