HPV Vaccine Not Linked to Autoimmune Disorders, Study Finds

There’s no increased risk of autoimmune disorders in girls who received quadrivalent human papillomavirus (HPV4) vaccination, according to a study published in CMAJ.

“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," Jeffrey Kwong, MD, a study author and a senior scientist at the Institute for Clinical Evaluative Sciences and at Public Health Ontario, said in a statement.

Human papillomavirus (HPV) is the most common sexually transmitted disease worldwide, affecting 50% to 75% of sexually active people.

Despite studies showing safety of the vaccine, there have been lingering concerns about a possible link to autoimmune disorders. A Canadian newspaper story alleging links to autoimmune disorders from the HPV vaccine was later retracted, the study noted, but doubts still persist among some parents, even though the vaccine is effective at protecting against 90% of the strains that cause cervical and anal cancer, penile cancer in men, as well as cancers of the mouth and throat.

In the United States, uptake of the HPV vaccine has never come close to reaching the Healthy People 2020 goal of 80% completion in both boys and girls by age 15 years. One recent study found that boys are not getting the vaccine because their doctors are not offering it. In addition, completion rates for girls are lagging, another study recently found.

To determine whether the HPV4 vaccination triggered autoimmune conditions, such as lupus, rheumatoid arthritis, type 1 diabetes, or 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 those, 180,819 received the vaccine and 110,120 did not.

Of those who did get vaccinated in school-based clinics, there were 681 diagnosed cases of autoimmune disorders between 1 week and 2 months after vaccination (n = 681; rate ratio [RR], 1.12; 95% CI, 0.85-1.47). This rate is consistent with the general rate of diagnosed cases in this age group. 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; RR, 1.73; 95% CI, 0.77-3.89), optic neuritis (n = 67; RR, 1.57; 95% CI, 0.74-3.33), and Graves disease (n = 47; RR, 1.55; 95% CI, 0.92-2.63).

Reference

Liu EY, Smith LM, Ellis AK, et al. Quadrivalent human papillomavirus vaccination in girls and the risk of autoimmune disorders: the Ontario grade 8 HPV vaccine cohort study. CMAJ. 2018;190(21):E648-E655. doi: 10.1503/cmaj.170871.