Further Evidence That HPV Vaccination Is Safe

The target age for immunizing girls with quadrivalent human papillomavirus (HPV) vaccine precedes the peak onset of multiple sclerosis (MS) and related demyelinating diseases, raising concern that the vaccine may cause MS. Investigators in Denmark and Sweden examined nationwide medical registry data from almost 4 million girls and women (age range, 10–44 years; 20% received HPV vaccine) to determine whether risk for MS was elevated during the 2-year period following vaccination.

In a cohort analysis adjusted for age, risk for MS (rate ratio, 0.9; 95% confidence interval, 0.7–1.2) or other demyelinating diseases (RR, 1.0; 95% CI, 0.8–1.3) was not increased after vaccination. A self-controlled case-series analysis (i.e., within-person comparis…