HPV vaccine-related thyroid adverse events: temporal patterns and reporting trends

Liying Song¹Jingkai Di²Jiaolin Fan¹Rongrong Xi³Siyu Liang³Guosheng Duan⁴Yuanzheng Ding¹Shuai Hao³Jing Liu^1*

• ¹First Hospital of Shanxi Medical University, Taiyuan, China
• ²Second Hospital of Shanxi Medical University, Taiyuan, China
• ³Shanxi Medical University, Taiyuan, China
• ⁴Fifth Hospital of Shanxi Medical University, Taiyuan, China

Background Human papillomavirus (HPV) vaccination is essential for cervical cancer prevention, but concerns about thyroid-related adverse events (AEs) have emerged. Method This pharmacovigilance study aimed to assess potential associations between HPV vaccination and thyroid disorders using spontaneous report data. Reports from the U.S. Vaccine Adverse Event Reporting System through December 31, 2024, were analyzed. Disproportionality analyses (PRR, ROR, BCPNN, MGPS) were performed, with subgroup analyses by gender, age, and vaccine type. A Weibull shape parameter model assessed the temporal risk pattern. Results Among 60,840 HPV vaccine-related reports, 13 thyroid-associated AEs showed positive signals. Hypothyroidism (ROR = 11.65) and autoimmune thyroiditis (ROR = 4.26) were the strongest signals. Most cases occurred in females under 65 years. HPV-4 was linked to 72.8% of thyroid AEs. The cumulative reporting rate reached 69.1% within 180 days. Conclusion Our findings suggest a potential association between HPV vaccination and thyroid disorders, notably hypothyroidism and autoimmune thyroiditis. Continued pharmacovigilance and further mechanistic investigations are needed.