Survey to Document the Adverse Reactions After Human Papillomavirus Vaccination Among Japanese Female Youth at a...

Concerns about possible adverse events remain a critical barrier in implementing human papillomavirus (HPV) vaccination among Japanese youth. This study aimed to understand the time course of adverse events experienced by HPV vaccine recipients.

An online questionnaire survey was given to students, faculty, and staff aged 18-26 years, at Okayama University Hospital, who received the HPV vaccine. The survey gathered information on the number of HPV vaccine doses received, prevaccination health conditions, adverse reactions within 2 h and between 2 h and 7 days postvaccination, menstrual irregularities after vaccination, reasons for getting vaccinated, feelings before and after vaccination, and factors providing reassurance during vaccination. Prevalence of symptoms was expressed as numbers and percentages, and analyses were performed using Chi-squared or Fisher's exact tests.

Responses were obtained from 299 participants, yielding a 75% response rate. Approximately 60% participants reported local pain, 30% swelling, and 4% fever. Most symptoms resolved on the vaccination day itself or the following day, although some persisted for 3-7 days. Over 80% participants rated their pain between 0 and 3 on numerical rating scale of 0-10. While 60% experienced anxiety before vaccination, 90% reported no anxiety afterward.

Our study presents one of the first comprehensive accounts of post-HPV vaccination adverse events and their time course, and underpins the importance of disseminating detailed information about vaccine-associated adverse reactions to encourage greater vaccine uptake.