Results from a study published early online in CANCER, a peer-reviewed journal of the American Cancer Society (ACS), demonstrates that a single dose of the human papillomavirus (HPV) vaccine may be as effective as multiple doses of the vaccine in preventing preinvasive cervical disease.
Preinvasive cervical disease, also referred to as cervical intraepithelial neoplasia (CIN) or cervical dysplasia, is a premalignant condition of the cervix caused by the Human Papilloma Virus (HPV). Because preinvasive cervical disease can, over time, develop into cervical cancer, this disease represents a major health problem for women.
Most common sexual transmitted infection
HPV is the most common sexually transmitted infection in the United States. Studies have shown that persistent infection with certain types of the virus can cause cervical cancer.
To prevent infection, the Centers for Disease Control and Prevention (CDC), the leading national public health institute of the United States, recommends that adolescents—both boys and girls under the age of 15 years 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 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.
The study results also demonstrated that 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.
“This study shows the impact of vaccinating at younger ages and its lasting long-term protection against cervical cancer,” Rodriguez said.
“It is important to educate parents about the need to vaccinate their children,” she added.
Public health implication
An accompanying editorial in the journal 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 fewer logistical setps…, available doses could extend further, and the overall cost would be lower,” Julia Brotherton and Karin Sundström, the authors of the editorial, concluded.
 Rodriguez AM, Zeybek B, Vaughn M, Westra J, Kaul S, Montealegre JR, Lin YL, Kuo YF. Comparison of the long-term impact and clinical outcomes of fewer doses versus standard doses of human papillomavirus vaccine in the United States: a database study.” CANCER; Published Online: February 10, 2020 (DOI: 10.1002/cncr.32700).
 Brotherton JML, Sundström K. More evidence suggesting that one dose human papillomavirus vaccination may be effective. CANCER; Published Online: February 10, 2020 (DOI: 10.1002/cncr.32696).