Vaccine
Talk

N.B. In Egypt, 4vHPV insert states that: 2-dose HPV vaccine schedule for adolescents who start the vaccination series before the 14th birthday.

How common is human papillomavirus (HPV) infection?

HPV is the most common sexually transmitted infection in the United States. HPV is so common that nearly all sexually active men and women contract the virus at some point in their lives. In the United States, more than 42 million people are infected with the types of HPV known to cause disease, and an estimated 13 million new HPV infections occur every year among people age 15 through 59 years. Approximately half of new infections occur among people age 15 through 24 years. The first HPV infection typically occurs within a few months to years of becoming sexually active.

How serious is disease caused by HPV?

Most HPV infections are asymptomatic and go away completely on their own within 2 years after infection (usually in the first 6 months) without causing clinical disease. Some infections are persistent and can lead to genital warts, precancerous lesions, or cancer. Infections caused by certain HPV types cause almost all cases of anogenital warts in women and men and recurrent respiratory papillomatosis.

Which types of HPV are most likely to cause disease?

CDC estimated that 36,500 people developed cancers attributable to HPV infections each year between 2015 to 2019. Of these annual cases, about 94% could have been prevented by the 9-valent HPV vaccine, including about 30,100 cases caused by HPV types 16 and 18 and 4,300 cases caused by HPV types 31, 33, 45, 52, and 58. HPV types 6 or 11 cause 90% of anogenital warts (condylomata) and most cases of recurrent respiratory papillomatosis.

Is there a treatment for HPV infection?

There is no treatment for infection with the HPV virus itself. Only HPV-associated lesions including genital warts, recurrent respiratory papillomatosis, precancers, and cancers are treated. Recommended treatments vary depending on the diagnosis, size, and location of the lesion. Local treatment of lesions might not eradicate all HPV-containing cells fully. It is unclear whether treating the lesion reduces the risk that the infected person could transmit the HPV infection to others.

Are healthcare personnel at risk of occupational infection with HPV?

Occupational infection with HPV is possible. Some HPV-associated conditions (including anogenital and oral warts, anogenital intraepithelial neoplasia, and recurrent respiratory papillomatosis) are treated with laser or electrosurgical procedures that could produce airborne particles. These procedures should be performed in an appropriately ventilated room using standard precautions and local exhaust ventilation. Workers in HPV research laboratories who handle wild-type viruses or "quasi virions" might be at risk of acquiring HPV from occupational exposures. In the laboratory setting, proper infection control should be instituted, including, at minimum, biosafety level 2. Whether HPV vaccination would be of benefit in these settings is unclear because no data exist on transmission risk or vaccine efficacy in this situation.

Can HPV be transmitted by non-sexual routes?

Nonsexual HPV transmission is theoretically possible but has not been definitively demonstrated. This is mainly because HPV can't be cultured, and DNA detection from the environment is difficult and likely prone to false negative results.

Reinfection with the same HPV strain?

Persistent infection means you cannot be reinfected with the same strain since you are continuously infected. After clearance, some—but not all—people have a lower chance of reinfection with the same strain; females are more likely than males to develop immunity after natural clearance. Prior infection does not lessen the chance of infection with a different HPV strain.

HPV vaccine recommendations for people age 9–26 years

Initiate routine HPV vaccination at age 11–12 years (may start at age 9; start at age 9 when risk of exposure is suspected). Vaccinate all people age 13–26 years who are not adequately vaccinated.

Are catch‑up recommendations different for males and females?

No. Since June 2019, routine catch‑up HPV vaccination is recommended for all previously unvaccinated or incompletely vaccinated males age 22–26, matching females. Recommendations differ by age and risk, not by biological sex.

Recommendations for age 27–45 years

Catch‑up HPV vaccination is not routinely recommended. Use shared clinical decision‑making for some adults who are not adequately vaccinated and want protection from ongoing risk. Vaccinate before potential exposure through sexual contact.

Why not routinely vaccinate all adults 27–45?

Because HPV is typically acquired soon after sexual debut, effectiveness is lower in older age groups due to prior infection, and exposure risk decreases with age. Population benefit is minimal, though some individuals might benefit.

Screen for prior HPV infection before vaccinating 27–45?

No. There is no laboratory screening test that determines type‑specific immunity. Vaccinate to prevent types to which the person remains susceptible.

Routine schedule for HPV vaccine

2‑dose schedule for those starting before the 15th birthday (separated by 6–12 months; minimum interval 5 months). 3‑dose schedule for those starting on/after the 15th birthday and for people with certain immunocompromising conditions: 0, 1–2 months, 6 months (minimums: 4 weeks between dose 1–2, 12 weeks between dose 2–3, and 5 months between dose 1–3). Do not restart if interrupted.

Extra 9vHPV doses after completing with 2vHPV/4vHPV?

No ACIP recommendation for additional 9vHPV doses after completing a series that included 9vHPV.

Revaccinate with 9vHPV after a completed 2vHPV/4vHPV series?

No. Revaccination with 9vHPV is not recommended for people who completed a recommended series of another HPV vaccine.

Pap smears still needed after vaccination?

Yes. Continue routine cervical cancer screening because the vaccine does not protect against all oncogenic HPV types.

Who needs a 3‑dose HPV schedule?

People age 9–26 years with primary or secondary immunocompromising conditions (for example, antibody or T‑cell defects, HIV, malignancy, transplantation, autoimmune disease, or immunosuppressive therapy). Use 3 doses even if starting at age 9–14 years.

Is asplenia an indication for 3 doses?

No. Asplenia alone is not an indication for a 3‑dose schedule, and neither are many chronic conditions unless immunosuppression is present.

Vaccine "failure" after prior infection?

HPV vaccines are >95% effective in people without prior infection to vaccine types. Infection with HPV types 16 and 18 after vaccination likely indicates exposure before vaccination. Vaccines do not treat existing infection or disease. 9vHPV protects against 9 HPV types.

Benefit after prior genital warts?

Yes. Prior warts indicate infection (usually types 6 or 11), but vaccination can protect against additional vaccine types not yet acquired. It has no therapeutic effect on existing infection or lesions. Complete the age‑appropriate series.

ACIP preference for 2‑dose vs 3‑dose in ages 9–14?

Yes. ACIP prefers the 2‑dose schedule for immunocompetent people starting before the 15th birthday.

Series delayed—restart?

Do not restart the series if doses are delayed. Resume and complete.

4‑day grace period?

Yes. A dose administered up to 4 days before the minimum interval may be counted as valid.

Invalid third dose timing example

If dose 3 was given 12 weeks after dose 2 but only 4 months after dose 1, repeat the third dose at 5 months after dose 1 or 12 weeks after the invalid dose—whichever is later.

Started before age 15 with >1 year since dose 1—need only one more?

Yes. If non‑immunocompromised and started before age 15, a single additional dose completes the series.

Two early doses (1–2 months apart) in adolescents—complete?

No. If the two doses are < 5 months apart, give a third dose 6–12 months after dose 1 and at least 12 weeks after dose 2.

Longest allowable interval before restarting?

There is no maximum interval that requires restarting. Resume where interrupted.

HPV vaccine and pregnancy

HPV vaccine is not recommended during pregnancy. Do not perform pregnancy testing prior to vaccination. If a dose was given during pregnancy, no intervention is needed; defer remaining doses until after pregnancy.

Vaccination given during unrecognized pregnancy—what next?

Withhold further HPV vaccine until after pregnancy, then complete the remaining doses using the usual 2‑ or 3‑dose schedule.

Coadministration with other vaccines?

Yes. HPV vaccine may be given with other inactivated or live vaccines at the same visit or any interval before/after because HPV vaccines are non‑live.

HPV vaccine given subcutaneously—repeat?

Yes. Repeat the dose by the intramuscular route; efficacy and duration data are based on IM administration.

Vaccinate after HPV detected on Pap?

Yes. Vaccinate women ≤ 26 years even with evidence of present/past infection; prior infection with one type does not protect from other types. Vaccination has no therapeutic effect on existing infection or lesions.

Breastfeeding and HPV vaccination?

Yes. Breastfeeding is not a contraindication to HPV vaccination.

Abnormal Pap history—contraindication?

No. Prior abnormal Pap is not a contraindication; vaccination can still protect against HPV types not yet acquired.