(HealthDay News) – For women vaccinated with the quadrivalent human papillomavirus vaccine (HPV4), there is no evidence of an autoimmune safety signal, according to a study published in the February issue of the Journal of Internal Medicine.
Chun Chao, PhD, from Kaiser Permanente Southern California in Pasadena, and colleagues conducted an observational study to assess the safety of HPV4 in women. A total of 189,629 women, who received one or more doses of HPV4 between August 2006 and March 2008, were followed for 180 days after each dose to identify new diagnoses of 16 prespecified autoimmune conditions. The incidence of each autoimmune condition observed in vaccinated women was compared with the incidence estimated for unvaccinated women at one study site.
The investigators identified 1,014 potential new-onset cases, of which 719 were eligible for review and 31–40% were confirmed. There were no clusters of disease onset in relation to vaccination. There was a significant increase only in the incidence rate ratio (IRR) for Hashimoto’s disease (IRR, 1.29; 95% CI, 1.08–1.56), but there was no consistent evidence for a safety signal for autoimmune thyroid conditions.
“This observational surveillance study offers some assurance that amongst a large and likely generalizable female population, no safety signal for autoimmune conditions was found following HPV4 vaccination in routine clinical use,” the authors write.
Several authors disclosed financial ties with pharmaceutical companies, including Merck & Co., which partially funded the study.