HPV vaccines were designed to prevent human papillomavirus (HPV) infection and the development of cervical precancers and cancer. Some research has suggested that HPV vaccines could help clear the virus in women already infected.
Allan Hildesheim, Ph.D., of the National Cancer Institute, Bethesda, Md., and colleagues conducted a study to address the question of whether women positive for HPV DNA should be encouraged to receive HPV-16/18 vaccination to induce or accelerate clearance of their infections. The trial was conducted in two provinces of Costa Rica and included 2,189 women age 18 to 25 years who were positive for HPV DNA. Participants were randomly assigned to receive three doses of HPV-16/18 vaccine (n = 1,088) or a control hepatitis A vaccine (n = 1,101) over 6 months.
There was no evidence that HPV vaccination significantly altered rates of viral clearance. At the 6-month visit, rates of clearance were 33.4 percent versus 31.6 percent for HPV-16/18 among participants who received the HPV vaccine and the control vaccine, respectively. At the 12-month visit, rates of clearance among participants in the HPV group and the control group, respectively, were 48.8 percent vs. 49.8 percent for HPV-16/18.
There was no evidence of vaccine effects with further analysis on selected study entry characteristics reflective of disease extent, including HPV-16/18 antibody results, cytologic results, and HPV viral load. Similarly, no evidence of vaccine effects was observed in analyses stratified by other study entry parameters thought to potentially influence clearance rates and efficacy of the vaccine, including time since sexual initiation, oral contraceptive use, cigarette smoking, and concomitant infection with Chlamydia trachomatis or Neisseria gonorrhoeae.
MEDICA.de; Source: JAMA and Archives Journals