Most people need either two or three doses of the HPV vaccine, depending on what age they start the series. Children who get their first shot between ages 9 and 14 need only two doses. Anyone who starts at age 15 or older needs three.
Two Doses: Ages 9 Through 14
If you (or your child) begin the HPV vaccine series before turning 15, the schedule is straightforward: two shots spaced 6 to 12 months apart. The immune system mounts a stronger response at younger ages, which is why fewer doses are needed. The minimum gap between the two doses is five months. If the second shot is given earlier than that, a third dose is required at least four months later to ensure full protection.
Three Doses: Age 15 and Older
Starting the series at age 15 or later means you’ll need three doses on a 0, 1 to 2, and 6 month schedule. In practical terms, that looks like this: get the first shot, return about one to two months later for the second, then come back roughly six months after the first shot for the third.
The minimum intervals matter if you’re trying to squeeze the series into a shorter window. You need at least four weeks between the first and second dose, at least 12 weeks between the second and third, and at least five months between the first and third. Doses given sooner than those minimums don’t count and need to be repeated.
The three-dose schedule also applies to anyone with a weakened immune system, including people living with HIV, regardless of the age they start. A developing immune system in a young child can build durable protection from two doses, but a compromised immune system at any age benefits from the extra shot.
Catch-Up Vaccination for Adults
The HPV vaccine is routinely recommended through age 26 for anyone who hasn’t completed the series. For adults between 27 and 45, the vaccine is available but typically involves a conversation with your doctor about whether it’s likely to benefit you. The reasoning: most people in that age range have already been exposed to common HPV strains, so the vaccine offers less new protection. But for some, particularly those with fewer prior sexual partners or new risk factors, it still makes sense. Adults in this range follow the same three-dose schedule.
What If You Missed a Dose?
You do not need to restart the series if there’s been a long gap between doses. This is true no matter how much time has passed. If you got your first shot two years ago and never went back, you can simply pick up where you left off. Your doctor will count whatever doses you’ve already received and schedule the remaining ones using the standard intervals.
One important detail: the number of doses you need is based on your age at the time of the first shot, not your current age. If you received your first dose at 13 but are now 16, you still only need two total doses because you started the series before 15.
The Global Shift Toward One Dose
Outside the United States, a significant shift is underway. The World Health Organization issued recommendations in 2022 supporting a single-dose HPV vaccine schedule based on growing evidence that one shot provides durable protection against cervical cancer. As of September 2024, 57 countries have adopted a single-dose schedule. The WHO estimates this approach allowed at least 6 million additional girls to receive HPV vaccination in 2023 alone, largely in lower-income countries where completing a multi-dose series is a major barrier.
The U.S. has not adopted this approach. The CDC still recommends two or three doses depending on age. But the global data on single-dose effectiveness is one reason researchers are optimistic that even an incomplete series offers meaningful protection, which is worth knowing if you’ve only received one shot and are debating whether to go back for more. Completing the full series remains the standard recommendation in the U.S. for the strongest, most reliable protection.
Quick Reference by Age
- Ages 9 to 14: 2 doses, given 6 to 12 months apart
- Ages 15 to 26: 3 doses at 0, 1 to 2, and 6 months
- Ages 27 to 45: 3 doses on the same schedule, based on individual discussion with a provider
- Immunocompromised (any age): 3 doses at 0, 1 to 2, and 6 months