Risk of autoimmune diseases and human papilloma virus (HPV) vaccines: Six years of case-referent surveillance.

BACKGROUND: Safety of HPV vaccines is still in question due to reports of autoimmune diseases (ADs) following HPV immunization.

OBJECTIVES: To assess the risk of ADs associated with HPV vaccination of female adolescents/young adults in France.

METHODS: Systematic prospective case-referent study conducted to assess the risks associated with real-life use of HPV vaccines. Cases were female 11-25 years old with incident ADs [central demyelination/multiple sclerosis (CD/MS), connective tissue disease (CTD), Guillain-Barré syndrome (GBS), type-1 diabetes (T1D), autoimmune thyroiditis (AT), and idiopathic thrombocytopenic purpura (ITP)]. Cases were consecutively and prospectively identified at specialized centers across France (2008-2014) and individually matched by age and place of residence to referents recruited in general practice. Risk was computed using multivariate conditional logistic regression models adjusted for family history of ADs, living in France (north/south), co-medications and co-vaccinations.

RESULTS: With a total of 478 definite cases matched to 1869 referents, all ADs combined were negatively associated to HPV vaccination with an adjusted odds ratio of 0.58 (95% confidence interval: 0.41-0.83). Similar results were obtained for CD/MS, AT, CT, and T1D, the last two not reaching statistical significance. No association was found for ITP and GBS. Sensitivity analyses combining definite and possible cases with secondary time window showed similar results.

CONCLUSION: Exposure to HPV vaccines was not associated with an increased risk of ADs within the time period studied. Results were robust to case definitions and time windows of exposure. Continued active surveillance is needed to confirm this finding for individual ADs.