Summary: Researchers report they have found no increased risk of autoimmune diseases in girls who received the HPV4 vaccine. The study adds to a growing body of evidence for the safety of the vaccine.
A new study in CMAJ (Canadian Medical Association Journal) found no increased risk of autoimmune disorders in girls who received quadrivalent human papillomavirus (HPV4) vaccination, adding to the body of evidence for the safety of the vaccine.
Human papillomavirus is the most common sexually transmitted disease worldwide, affecting 50%-75% of sexually active people. The HPV4 vaccine is effective at protecting against 90% of the strains that cause cervical and anal cancer. Despite studies showing safety of the vaccine, there have been concerns about a possible link to autoimmune disorders.
“Despite demonstrated effectiveness in real-world settings, concerns continue to persist regarding the safety of the HPV4 vaccine. In light of these concerns, we wanted to study the HPV4 vaccination since it was being offered free to all grade 8 girls in Ontario through school-based clinics,” says Dr. Jeffrey Kwong, a study author and a senior scientist at the Institute for Clinical Evaluative Sciences (ICES) and at Public Health Ontario.
To determine whether the HPV4 vaccination triggered autoimmune conditions such lupus, rheumatoid arthritis, type 1 diabetes and multiple sclerosis, researchers looked at data on 290 939 girls aged 12 to 17 years in Ontario who were eligible for vaccination between 2007 and 2013. Of the total 180 819 girls who received the HPV4 (Gardasil and Merck) vaccination in school-based clinics, there were 681 diagnosed cases of autoimmune disorders between one week and two months after vaccination. This rate is consistent with the general rate of diagnosed cases in this age group.
“These findings add to the body of evidence on the safety of the HPV4 vaccine and should reassure parents and health care providers,” says Dr. Linda Lévesque, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario.
About this neuroscience research article
Funding: The study was funded by the Ontario Ministry of Health and Long-Term Care, Drug Innovation Fund and the Canadian Institutes of Health Research (CIHR).
Source: Kim Barnhardt – CMAJ Publisher: Organized by NeuroscienceNews.com. Image Source: NeuroscienceNews.com image is in the public domain. Original Research: Open access research for “Quadrivalent human papillomavirus vaccination in girls and the risk of autoimmune disorders: the Ontario Grade 8 HPV Vaccine Cohort Study” by Erin Y. Liu, Leah M. Smith, Anne K. Ellis, Heather Whitaker, Barbara Law, Jeffrey C. Kwong, Paddy Farrington and Linda E. Lévesque in Canadian Medical Association Journal. Published May 28 2018. doi:10.1503/cmaj.170871
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[cbtabs][cbtab title=”MLA”]CMAJ “No Link Between HPV Vaccine and Autoimmune Disorder Risk.” NeuroscienceNews. NeuroscienceNews, 28 May 2018. <https://neurosciencenews.com/hpv-vaccine-autoimmune-9156/>.[/cbtab][cbtab title=”APA”]CMAJ (2018, May 28). No Link Between HPV Vaccine and Autoimmune Disorder Risk. NeuroscienceNews. Retrieved May 28, 2018 from https://neurosciencenews.com/hpv-vaccine-autoimmune-9156/[/cbtab][cbtab title=”Chicago”]CMAJ “No Link Between HPV Vaccine and Autoimmune Disorder Risk.” https://neurosciencenews.com/hpv-vaccine-autoimmune-9156/ (accessed May 28, 2018).[/cbtab][/cbtabs]
Quadrivalent human papillomavirus vaccination in girls and the risk of autoimmune disorders: the Ontario Grade 8 HPV Vaccine Cohort Study
BACKGROUND: Despite 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.
METHODS: We 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.
RESULTS: The 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).
INTERPRETATION: We did not observe an increased risk of autoimmune disorders following HPV4 vaccination among teenaged girls. These findings should reassure parents and health care providers.
Human papillomavirus (HPV) is the most common sexually transmitted infection globally affecting 50%–75% of sexually active individuals. The quadrivalent HPV (HPV4) vaccine protects against 2 oncogenic strains of HPV and has been available since 2006. Despite demonstrated effectiveness in real-world settings including proven reduction in the risk of cervical dysplasia, concerns persist about the vaccine’s safety, particularly in light of case reports of autoimmune disorders following HPV vaccination.
A recent news story reporting cases of serious debilitating illnesses after HPV4 — although subsequently retracted — reactivated parental concerns about the safety of this vaccine. As such, we undertook a population-based, retrospective cohort study to assess the risk of autoimmune disorders following HPV4 vaccination among grade 8 girls eligible for Ontario’s HPV vaccination program.