(HealthDay News) — Quadrivalent human papillomavirus (HPV) vaccination of girls and women aged 10 to 30 years is associated with a reduced risk for invasive cervical cancer, according to a study published in the Oct. 1 issue of the New England Journal of Medicine.
Jiayao Lei, Ph.D., from the Karolinska Institutet in Stockholm, and colleagues used nationwide Swedish demographic and health registers to follow 1,672,983 girls and women aged 10 to 30 years from 2006 through 2017, until their 31st birthday. The association between HPV vaccination and risk for invasive cervical cancer was examined.
The researchers found that cervical cancer was diagnosed in 19 and 538 women who had and had not received the quadrivalent vaccine, respectively. The cumulative incidence of cervical cancer was 47 and 94 cases per 100,000 persons among women who had and had not been vaccinated, respectively. For the comparison of the vaccinated population with the unvaccinated population, the incidence rate ratio was 0.51 (95 percent confidence interval [CI], 0.32 to 0.82) after adjustment for age at follow-up and 0.37 (95 percent CI, 0.21 to 0.57) after additional adjustment for other covariates. The incidence rate ratio was 0.12 (95 percent CI, 0.00 to 0.34) among women who had been vaccinated before age 17 years and 0.47 (95 percent CI, 0.27 to 0.75) among women who had been vaccinated at ages 17 to 30 years, after adjustment for all covariates.
“Our results extend this knowledge base by showing that quadrivalent HPV vaccination is also associated with a substantially reduced risk of invasive cervical cancer, which is the ultimate intent of HPV vaccination programs,” the authors write.