What are the current guidelines for human papillomavirus (HPV) vaccination, including recommended ages, dosing schedules for Gardasil 9 (9‑valent HPV vaccine), contraindications, and recommendations for pregnant or immunocompromised patients?

HPV Vaccination Guidelines

Routine Vaccination Age and Schedule

All children should receive routine HPV vaccination at age 11–12 years (can start as early as age 9), with the number of doses determined by age at first dose: 2 doses for those starting before age 15, and 3 doses for those starting at age 15 or older. 1, 2

Two-Dose Schedule (Age 9–14 Years)

• Administer the first dose at age 11–12 years (can begin at age 9) 2
• Give the second dose 6–12 months after the first dose, with a minimum interval of 12 weeks 2
• Longer intervals approaching 12 months produce stronger antibody responses than shorter intervals 2
• Younger adolescents (9–14 years) generate significantly higher antibody titers than older individuals receiving 3 doses, which supports the reduced-dose schedule 2

Three-Dose Schedule (Age ≥15 Years)

• Required for all persons initiating vaccination at age 15 years or older 2
• Dose 1: Day 0 2
• Dose 2: 1–2 months after first dose (minimum 4 weeks) 2
• Dose 3: 6 months after first dose (minimum 12 weeks after dose 2) 2

Catch-Up Vaccination

Catch-up HPV vaccination is recommended for all persons through age 26 years who are not adequately vaccinated, regardless of prior sexual activity or HPV exposure. 1

• Most sexually active adults have been exposed to some HPV types but not all vaccine-covered types 1
• No clinical antibody test can determine immunity to specific HPV types 1
• History of genital warts, abnormal Pap tests, or positive HPV DNA tests are not contraindications to vaccination 1, 2

Adults Aged 27–45 Years

• For adults aged 27–45 years, shared clinical decision-making is recommended rather than universal vaccination, as the public health benefit is minimal in this age range 1
• The number needed to vaccinate increases from 202 (routine program) to 6,500 when extending to age 45 2
• Factors favoring vaccination: new or anticipated sexual partners, men who have sex with men, immunocompromising conditions, limited lifetime sexual partners 2
• Factors against vaccination: long-term mutually monogamous relationships, extensive prior HPV exposure 2
• HPV vaccines are not licensed for use beyond age 45 years 2

Special Populations

Immunocompromised Persons

All immunocompromised individuals require a 3-dose schedule regardless of age at initiation. 2

• This includes persons with HIV infection, solid organ transplant recipients, and those on immunosuppressive therapy 2
• Seroconversion rates are lower (53–68% per HPV type) compared to immunocompetent individuals 2

Men Who Have Sex With Men

• Vaccination is recommended through age 26 years for men who have sex with men due to high burden of HPV-related anal cancer and precancers 1, 3
• Vaccine efficacy against anal intraepithelial neoplasia grades 2/3 approaches 90% 3

Pregnancy and Breastfeeding

• Vaccination should be delayed until after pregnancy 1
• Pregnancy testing is not required before vaccination 1
• Women who are breastfeeding can receive HPV vaccine 1, 4
• If pregnancy occurs during the vaccination series, postpone remaining doses until after delivery 2

Current Vaccine Product

Gardasil 9 (9-valent HPV vaccine) is the only HPV vaccine available in the United States as of January 2017. 2

• Protects against HPV types 6,11,16,18,31,33,45,52, and 58 2
• Prevents approximately 90% of cervical cancers (compared to 70% with earlier vaccines) 2
• Prevents approximately 90% of genital warts caused by HPV types 6 and 11 2, 3
• Administered as 0.5 mL intramuscular injection into the deltoid muscle 2

Pre-Vaccination Testing

No laboratory or clinical testing is required before HPV vaccination. 2

• Do not perform Pap smears, HPV DNA tests, or HPV antibody tests before vaccination 1, 2
• HPV testing before initiating vaccination is not recommended 1

Contraindications and Precautions

• History of immediate hypersensitivity to yeast or any vaccine component 2
• Moderate or severe acute illness (defer vaccination) 2
• Patients should sit or lie down for 15 minutes after vaccination due to syncope risk in adolescents 2
• Most common adverse effect is headache (up to 50% of recipients) 2

Interrupted Vaccination Series

If the vaccination series is interrupted, continue from where you left off without restarting the series. 2

• The critical factor is the age at first dose, not when subsequent doses are administered 2
• No maximum time interval exists between doses 2
• Maintain minimum intervals: 4 weeks between doses 1 and 2, and 12 weeks between doses 2 and 3 2

Cancer Prevention Impact

HPV vaccination prevents approximately 28,500–31,200 cancers annually in the United States. 2

• Virtually all cervical cancers (100%) 2
• Approximately 90% of anal cancers 2
• Approximately 70% of oropharyngeal cancers 2
• 60–70% of vaginal, vulvar, and penile cancers 2

Cervical Cancer Screening

Cervical cancer screening must continue for all women regardless of vaccination status, as the vaccine does not protect against all oncogenic HPV types. 1, 2

• Screening recommendations have not changed for vaccinated individuals 2
• Each healthcare visit where vaccination is discussed represents an opportunity to offer Pap screening to sexually active patients 1

Timing Considerations

Vaccination is most effective when administered before sexual debut, as approximately 24% of adolescents report sexual activity by 9th grade and 58% by 12th grade. 2

• HPV infection incidence approaches 40% within 2 years after first sexual intercourse 2
• However, sexually active individuals should still receive age-appropriate vaccination because they are unlikely to have been infected with all vaccine-covered HPV types 1, 2

Common Pitfalls to Avoid

• Do not delay vaccination waiting for "optimal" timing—vaccinate at the recommended age 2
• Do not restart an interrupted series—continue from the point of interruption 2
• Do not withhold vaccination from sexually active individuals 1, 2
• Do not assume prior HPV exposure is a contraindication 1, 2
• Do not discontinue cervical cancer screening in vaccinated women 1, 2