• Erin Y Liu, Leah M Smith, Anne K Ellis, Heather Whitaker, Barbara Law, Jeffrey C Kwong, Paddy Farrington, and Linda E Lévesque.
• Department of Public Health Sciences (Liu, Lévesque), Queen's University, Kingston, Ont.; Department of Epidemiology, Biostatistics and Occupational Health (Smith), McGill University, Montréal, Que. Division of Allergy and Immunology, Department of Medicine (Ellis), Queen's University, Kingston, Ont.; Allergy Research Unit (Ellis), Kingston General Hospital, Kingston, Ont.; School of Mathematics and Statistics (Whitaker, Farrington), The Open University, Milton Keynes, UK; Vaccine Safety Section, Centre for Immunization and Respiratory Infectious Diseases (Law [retired from the Public Health Agency of Canada June 2015]), Public Health Agency of Canada, Ottawa, Ont.; Institute for Clinical Evaluative Sciences (Kwong, Lévesque), Toronto, Ont.; Public Health Ontario (Kwong), Toronto, Ont.; Department of Family and Community Medicine (Kwong), University of Toronto, Toronto, Ont.; Leslie Dan Faculty of Pharmacy (Lévesque), University of Toronto, Toronto, Ont.
• CMAJ. 2018 May 28; 190 (21): E648E655E648-E655.

BackgroundDespite demonstrated effectiveness in real-world settings, concerns persist regarding the safety of the quadrivalent human papillomavirus (HPV4) vaccine. We sought to assess the risk of autoimmune disorders following HPV4 vaccination among grade 8 girls eligible for Ontario's school-based HPV vaccination program.MethodsWe undertook a population-based retrospective cohort study using Ontario's administrative health and vaccination databases from 2007 to 2013. The self-controlled case series method was used to compare the rate of a composite end point of autoimmune disorders diagnosed during days 7-60 post-vaccination ("exposed" follow-up) to that at any other time ("unexposed"). The analysis was repeated to assess the effect of a history of immune-mediated diseases and time since vaccination. We also conducted an exploratory analysis of individual autoimmune disorders. Rate ratios and 95% confidence intervals (CIs) were estimated using conditional Poisson regression, adjusted for age, seasonality, concomitant vaccinations and infections.ResultsThe study cohort consisted of 290 939 girls aged 12-17 years who were eligible for vaccination between 2007 and 2013. There was no significant risk for developing an autoimmune disorder following HPV4 vaccination (n = 681; rate ratio 1.12, 95% CI 0.85-1.47), and the association was unchanged by a history of immune-mediated disorders and time since vaccination. Exploratory analyses of individual autoimmune disorders found no significant risks, including for Bell palsy (n = 65; rate ratio 1.73, 95% CI 0.77-3.89), optic neuritis (n = 67; rate ratio 1.57, 95% CI 0.74-3.33) and Graves disease (n = 47; rate ratio 1.55, 95% CI 0.92-2.63).InterpretationWe did not observe an increased risk of autoimmune disorders following HPV4 vaccination among teenaged girls. These findings should reassure parents and health care providers.© 2018 Joule Inc. or its licensors.

26 keywords...

hide…