Research Assistant Professor National Institute of Health Data Science, Peking University Beijing, China (People's Republic)
Background: The 9-valent human papillomavirus (9vHPV; Gardasil 9 [Merck & Co., Inc., Rahway, NJ, USA]) vaccine was introduced in China in 2018. However, the safety of the 9vHPV vaccine administered to Chinese women as part of routine health care has previously not been studied.
Objectives: To monitor the occurrence of new-onset autoimmune diseases and adverse pregnancy outcomes in Chinese women who received the 9vHPV vaccine.
Methods: A post-marketing surveillance of females who received the first dose of the 9vHPV vaccine at age 16-26 years in Ningbo city between January 25th, 2019 to March 31st, 2021 was performed within the Ningbo Regional Health Information Platform (NRHIP). New-onset cases of Graves’ disease, Hashimoto’s thyroiditis, systemic lupus erythematosus, type 1 diabetes, multiple sclerosis, optic neuritis, and uveitis diagnosed within 6 months after each dose or between two doses (time interval ≤6 months) of the 9vHPV vaccine were to be reported. For adverse pregnancy outcomes, cases of stillbirth in women who received the 9vHPV vaccine within 30 days before conception or during pregnancy were to be reported as well as cases of 23 major congenital anomalies diagnosed within 3 months from birth in infants whose mothers had maternal exposure to 9vHPV vaccine were also reported.
Results: A total of 102,670 doses of the 9vHPV vaccine were administered to 41,609 women aged 16-26 years old who had received no other HPV vaccine. Sixteen women received a mixed 4vHPV/9vHPV regimen (55 doses). New-onset autoimmune disorders were diagnosed in 36 women, comprising 21 cases of Hashimoto’s disease (incidence density, 78.94 per 100,000 person-years), 11 cases of Graves’ disease (41.34 per 100,000 person-years), and 4 cases of uveitis (15.03 per 100,000 person-years). Among the 50 women with 9vHPV maternal exposure, no stillbirths were observed. One case of microtia was reported in an infant whose mother had maternal exposure. No cases of autoimmune disorders and no pregnancies were observed in women who had received a mixed 4vHPV/9vHPV regimen.
Conclusions: In this first post-marketing surveillance for the safety of the 9vHPV vaccine in China, no safety signals of new-onset autoimmune disorders or adverse pregnancy outcomes were observed. These findings confirm the favorable benefit/risk profile of the 9vHPV vaccine in Chinese women in the routine healthcare setting.
