One and⁢ Done? New Study Suggests that One dose of HPV Vaccine⁣ might potentially⁣ be Enough

⁢ Updated May 25, 2025
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A large-scale study indicates that one ⁤dose of ‍the HPV vaccine may provide sufficient protection against HPV and related conditions like cervical cancer. The study ⁤results ‍were ⁤presented at the American Cancer Society meeting and ⁤are under review by the Advisory Committee ⁤on Immunization Practices (ACIP).

When the HPV⁢ vaccine debuted in 2006, experts recommended three doses for optimal immunity. the schedule involved a second dose one month ⁣after the first, followed by a third dose six months ⁣later. Adherence to this schedule proved challenging for some, leading to incomplete⁣ vaccinations.

research over the past⁤ two decades⁤ has suggested that three doses may not ‍be necessary. early studies demonstrated that two doses offered similar protection, particularly‍ in younger individuals with stronger immune responses. In 2016, the ACIP updated its guidelines, recommending ⁣two doses for individuals starting the vaccine series before age 15. The current study may prompt further revisions to the vaccination schedule.

HPV Vaccine Study—One Shot Compared to Two

The ESCUDDO trial, launched in Costa Rica in 2017, enrolled over 20,000 girls aged 12-15. Participants were ⁣randomly assigned to four groups. The first group received one dose of Cervarix, a vaccine protecting against the two HPV types most linked to cervical cancer. ⁢The second group received two Cervarix doses. The third group received one dose of Gardasil 9, protecting against⁤ nine HPV‍ strains associated with cancer or genital warts. The fourth group received two Gardasil 9 doses. ‍(Cervarix is no longer available in the United ⁤States but is still used in other countries.)

The young women were monitored every six months, undergoing HPV⁣ infection testing of the cervix and blood tests to detect HPV antibodies. Researchers observed⁣ no significant differences in these factors between those receiving one or two doses of either vaccine.

Researchers also⁢ enrolled unvaccinated women ages 16-22 from the same areas. These⁤ women attended three study visits ‍six months‍ apart to⁣ determine their HPV DNA ⁤status. For ethical reasons, they were offered HPV ‍vaccination each time. Researchers compared these test results to all of the study groups to get ‍a⁣ sense of how many potential cases of HPV were avoided because of the vaccines. They‍ also looked at whether this was different in people who got one ⁢or two doses of their vaccine. It ⁢was⁣ not.

The researchers concluded that one ⁢dose was ⁣as effective as two for both vaccines. This aligns with findings from ⁢similar studies worldwide.⁤ A 2016 Indian study found that one dose of an earlier Gardasil version provided sufficient protection. A⁤ randomized trial in Kenya showed that⁤ one dose of Gardasil 9 or Cervarix was 98% ⁢effective in preventing HPV 16/18 infection for up to three years post-vaccination.

What‍ a Change‍ to One Shot Could Mean

Adopting a single-dose HPV vaccine regimen could boost vaccine uptake by removing barriers like⁤ transportation and time off work.It would also streamline large-scale vaccination efforts, particularly in resource-limited countries.

The⁢ ACIP discussed one-dose ⁢HPV vaccination at its April meeting and may revise its recommendations‍ at ⁢its next meeting in June. Though, anti-vaccine sentiment within the Department of health and Human Services and CDC funding cuts could complicate this process.

What’s next

The ACIP ⁤is expected to further discuss and potentially vote on the single-dose HPV vaccine recommendation at its June meeting.