Suspected adverse effects after human papillomavirus vaccination: a temporal relationship.

In Japan, a significant number of adolescent girls complained unusual symptoms after human papillomavirus (HPV) vaccination, and the vast majority of them were initially diagnosed as having psychiatric illness because of the absence of pathologic findings, radiological images and specific abnormalities in laboratory test results. Later, these symptoms were supposed to be adverse effects after HPV vaccination, and the recommendation for HPV vaccination was withdrawn by Japanese Ministry of Public Health, Labour and Welfare 4 years and 9 months ago. However, a causal link has not been demonstrated between HPV vaccination and the development of these symptoms. Our study has shown that the period of HPV vaccination considerably overlapped with that of unique postvaccination symptom development, adding that new patients with possible HPV vaccine-related symptoms have not appeared during our recent 28-month follow-up period. This social episode has now subsided in Japan.