What is the recommended Human Papillomavirus (HPV) vaccination schedule for an unvaccinated adult with no known history of HPV infection?

HPV Vaccination for Adults

Adults initiating HPV vaccination require either 2 or 3 doses depending on their age at first dose: 2 doses if starting before age 15, or 3 doses if starting at age 15 or older. 1

Age-Based Dosing Schedule

For Adults Who Started Before Age 15

• Only 2 doses total are needed, administered at 0 and 6-12 months apart 1
• The critical factor is the age when the first dose was given, not when subsequent doses are administered 1
• Even if there are long delays between doses, the series does not need to be restarted 1

For Adults Starting at Age 15 or Older

• 3 doses are required, administered at 0,1-2, and 6 months 1, 2
• Minimum intervals: 4 weeks between doses 1 and 2, and 12 weeks between doses 2 and 3 1
• This 3-dose schedule applies to all adults through age 26 years 1, 3

Special Populations Requiring 3 Doses

Immunocompromised individuals always require 3 doses regardless of age at initiation, including: 1, 3

• HIV-positive individuals 3
• Solid organ transplant recipients 1
• Other immunocompromising conditions 1

Age Limits and Recommendations

Routine Catch-Up Vaccination

• Catch-up vaccination is recommended for all persons through age 26 years who are not adequately vaccinated 1, 3
• This applies to both males and females 4

Ages 27-45 Years

• Routine vaccination is NOT recommended for all adults in this age group 3
• Shared clinical decision-making may be considered, but the American Cancer Society explicitly does not endorse this due to minimal benefit 3
• Vaccination effectiveness decreases dramatically after age 26, with only 0.5% additional cancer prevention estimated 3

Over Age 45

• HPV vaccines are not licensed for use in adults over age 45 years 3

Important Clinical Considerations

Prior HPV Exposure Does Not Preclude Vaccination

• History of genital warts, abnormal Pap tests, or positive HPV DNA tests are NOT contraindications to vaccination 5, 3
• Most sexually active adults have been exposed to some HPV types but not all vaccine types 3
• The vaccine protects against HPV types not yet acquired 1

Interrupted Series

• Never restart the series regardless of delay length 1
• Simply continue from where you left off, maintaining minimum intervals 1
• There is no maximum time interval between doses 1

Pregnancy and Breastfeeding

• Vaccination should be delayed until after pregnancy 3
• Breastfeeding women can safely receive the vaccine 3

Common Pitfalls to Avoid

• Do not delay vaccination waiting for "optimal" timing - approximately 24% of adolescents report sexual intercourse by 9th grade 1
• Do not perform pre-vaccination testing - no HPV DNA testing, antibody testing, or Pap testing is needed before administering doses 1
• Do not skip cervical cancer screening in vaccinated individuals - vaccines do not protect against all oncogenic HPV types 1, 3

Key Limitation

HPV vaccines are prophylactic only - they prevent new infections but do not treat existing HPV infections or HPV-related diseases 3