Frisch M, et al. - Whether quadrivalent human papillomavirus (qHPV) vaccination of 10–17-year-old boys is associated with any unusual risk of autoimmune diseases, neurological diseases or venous thromboembolism was investigated herein. Results of this investigation offered population-based reassurance that an elevated risk of autoimmune diseases, neurological diseases or venous thromboembolism is unlikely to be seen in relation to qHPV vaccination of 10–17-year-old boys.