HPV Vaccination for a 15-Year-Old After First Dose
Yes, a 15-year-old who received only one dose of HPV vaccine needs two additional doses to complete the series, for a total of three doses. 1
Age-Based Dosing Schedule
The critical determining factor is the age when the first dose was administered, not the patient's current age. 1
- If the first dose was given before age 15: Only 2 doses total are needed (second dose 6-12 months after the first) 1, 2
- If the first dose was given at age 15 or older: 3 doses total are required (at 0,1-2, and 6 months) 3, 1, 2
Since your patient received the first dose at age 15, she falls into the 3-dose schedule category and requires two more doses to be adequately vaccinated. 1
Completing the Series
The remaining doses should be administered as follows:
- Second dose: 1-2 months after the first dose (minimum 4 weeks) 1
- Third dose: 6 months after the first dose (minimum 12 weeks after the second dose) 1
If the vaccination series has been interrupted, do not restart—simply continue from where you left off, maintaining the minimum intervals. 1 The series does not need to be restarted regardless of how much time has elapsed. 1
Why Three Doses at Age 15+?
The 2-dose schedule for younger adolescents (ages 9-14) is based on robust immunogenicity data showing that younger individuals mount significantly stronger antibody responses than older individuals receiving 3 doses. 1 However, those who initiate vaccination at age 15 or older require the full 3-dose series to achieve adequate protection. 3, 1
Common Pitfall to Avoid
Do not assume she only needs one more dose simply because she is still an adolescent. The ACIP explicitly states that individuals who initiated the series before age 15 and received only one dose are not considered adequately vaccinated and should receive additional doses according to the age-at-initiation schedule. 3 Since she started at age 15, she needs the full 3-dose series. 1
Clinical Urgency
Approximately 24% of adolescents report sexual intercourse by 9th grade, and 58.1% by 12th grade. 3, 1 HPV infection incidence is nearly 60% within 2 years after sexual initiation. 1 Therefore, completing the vaccination series promptly is critical to maximize protection before potential HPV exposure. 1