A new study assessed whether quadrivalent human papillomavirus (qHPV) vaccination is associated with increased incidence of new-onset autoimmune disease in girls and women with pre-existing autoimmune disease.

This register-based open cohort study included all girls and women between 10 and 30 years of age in Sweden in 2006–2012 diagnosed with at least one of 49 prespecified autoimmune diseases. A total of 70 265 girls and women had at least one of the 49 predefined autoimmune diseases; 16% of these individuals received at least one dose of qHPV vaccine.

Incidence rate ratios were estimated for new-onset autoimmune disease within 180 days of qHPV vaccination using Poisson regression adjusting for, country of birth, parental country of birth, parental income and parental education.

In unvaccinated girls and women, 5428 new-onset autoimmune diseases were observed during 245,807 person-years at a rate of 22.1 new events per 1000 person-years. In vaccinated girls and women, there were 124 new events during 7848 person-years at a rate of 15.8 per 1000 person-years. There was no increase in the incidence of new-onset autoimmune disease associated with qHPV vaccination during the risk period; on the contrary, they found a slightly reduced risk.

Vaccination with HPV did not increase the risk of developing another autoimmune disease. In fact, being vaccinated was associated with a slightly reduced risk compared with not being vaccinated.

Dr. Lisen Arnheim-Dahlstrom, senior author of the Journal of Internal Medicine study, noted that individuals with autoimmune disease are vulnerable to vaccine-preventable diseases.