New research indicates that a single dose of the HPV vaccine may be as effective as multiple doses for preventing preinvasive cervical disease (Cancer [Epub Feb 10, 2020]. https://doi.org/10.1002/cncr.32700).

HPV is the most common sexually transmitted infection in the United States, and persistent infection with certain types of the virus can cause cervical cancer. To prevent infection, the CDC recommends that adolescents—both boys and girls—younger than 15 years of age receive a two-dose schedule of the HPV vaccine. To determine the effectiveness of other dose schedules, Ana M. Rodriguez, MD, MPH, of the University of Texas Medical Branch at Galveston, and her colleagues examined information on females aged 9 to 26 years, who were unvaccinated or who received one or more HPV vaccine doses between January 2006 and June 2015.

The analysis included 133,082 females (66,541 vaccinated and 66,541 unvaccinated). For females aged 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 for 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 (<15 years of age) 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.

“This study shows the impact of vaccinating at younger ages and its lasting long-term protection against cervical cancer,” Dr. Rodriguez said. “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, the authors noted, this would decrease the costs and probably increase the vaccination rate.

—Ethan Covey