A single dose of the human papillomavirus (HPV) vaccine is as effective as multiple doses for preventing preinvasive cervical disease that can later develop into cervical cancer, according to a new study.

In the UK, girls and boys aged 12 to 13 years will be routinely offered two doses of HPV vaccination with the second dose normally offered 6 to 12 months after the first.

The study was published in CANCER, a journal of the American Cancer Society, and included 133,082 females aged 9 to 26 years who were unvaccinated  (66,541) or who received one or more HPV vaccine (66,541) doses between January 2006 and June 2015.

One dose of HPV vaccination would allow better scale-up

For females ages 15 to 19 years, those who received one, two, or three doses of the HPV vaccine had lower rates of preinvasive cervical disease than adolescents who were unvaccinated. Within five years, 2.65% of unvaccinated teens aged 15 to 19 years developed preinvasive cervical disease, compared with 1.62%, 1.99%, and 1.86% in the one-, two- and three-dose groups, respectively.

The risk of preinvasive cervical disease was 36%, 28%, and 34% lower for adolescents who received one, two, and three doses, respectively, compared with adolescents who were unvaccinated.

For the youngest (less than 15 years old) and oldest age groups (20 years and older), the investigators did not find significant differences among the vaccinated groups in terms of risk for preinvasive cervical disease.

Study author Ana M. Rodriguez, University of Texas Medical Branch at Galveston, said : “This study shows the impact of vaccinating at younger ages and its lasting long-term protection against cervical cancer. It is important to educate parents about the need to vaccinate their children.”

An accompanying editorial discusses the public health implications of the study’s findings. “If one dose of HPV vaccine was sufficient for effective protection, HPV vaccine implementation and scale-up would require less logistics…, available doses could extend further, and the overall cost would be lower,” the authors wrote.