What is the minimum interval between the second and third doses of the HPV vaccine for individuals who start the series at age 15 years or older (or are immunocompromised)?

Minimum Interval Between 2nd and 3rd HPV Vaccine Doses

For individuals starting the HPV vaccine series at age 15 years or older (or those who are immunocompromised at any age), the minimum interval between the second and third doses is 12 weeks. 1, 2, 3

Dosing Schedule Requirements

Three-Dose Schedule Intervals

• First to second dose: Minimum 4 weeks 1, 3
• Second to third dose: Minimum 12 weeks (approximately 3 months) 1, 2, 3
• First to third dose: Minimum 24 weeks (6 months from first dose) 2

The standard timing is 0,1-2 months, and 6 months, but these are the absolute minimum acceptable intervals. 1, 2

Who Requires the Three-Dose Schedule

• Anyone initiating vaccination at age 15 years or older 1, 2, 3
• All immunocompromised individuals regardless of age at initiation, including HIV-positive persons and solid organ transplant recipients 1

Critical Clinical Considerations

Managing Interrupted Series

• Never restart the series regardless of how long the interruption lasts between doses 1, 2, 3
• If interrupted after the first dose, administer the second dose as soon as possible 1, 2
• The only requirement is maintaining the minimum 12-week interval between doses 2 and 3 1, 2, 3
• There is no maximum time interval between doses—the vaccine does not "expire" or lose effectiveness if doses are delayed 1

Longer Intervals May Be Beneficial

• Evidence demonstrates that longer intervals between doses produce stronger antibody responses than shorter intervals 1, 4, 5
• A 12-month interval between doses generates more robust antibody responses than a 6-month interval, which is superior to a 2-month interval 1
• Research shows that alternate schedules with extended intervals (0,2,12 months) are non-inferior and may be superior to standard schedules 4, 5

Common Pitfalls to Avoid

• Do not delay vaccination waiting for "optimal" timing once minimum intervals are met, as approximately 24% of adolescents report sexual intercourse by 9th grade 1, 3
• Do not restart the series if interrupted—continue from where you left off while maintaining minimum intervals 1, 2, 3
• Do not withhold vaccination from sexually active individuals, as they are unlikely to have been infected with all vaccine HPV types and will still benefit from protection against types not yet acquired 1, 2