Post-marketing surveillance for the safety of the quadrivalent human papillomavirus vaccine: a retrospective real-world study in China

The potential occurrence of autoimmune- and pregnancy-related adverse events with the quadrivalent human papillomavirus (4vHPV) vaccine has previously not been assessed in the real-world setting in China. A retrospective active post-marketing surveillance of the 4vHPV vaccine has been conducted among Chinese women aged 20-45 years between January 2018 and March 2021 in the Ningbo city. Incidences of seven pre-specified autoimmune diseases diagnosed within 6 months after the 4vHPV vaccination were calculated. Cases of stillbirth and 23 congenital anomalies diagnosed within 3 months from birth in infants were collected in women with maternal exposure to the 4vHPV vaccine. A total of 195,593 doses of the 4vHPV vaccine were administered to 76,212 women. New-onset cases of autoimmune diseases were diagnosed in 113 women, comprising 71 cases of Hashimoto's disease (130.84/100,000 person-years), 24 cases of Graves' disease (44.21/100,000 person-years), 1 case of optic neuritis (1.84/100,000 person-years), and 17 cases of uveitis (31.31/100,000 person-years). Among the 168 women with maternal exposure to the 4vHPV vaccine, five cases of congenital heart disease were observed in their infants. These findings confirm the favorable benefit/risk profile of the 4vHPV vaccine in Chinese women in the routine healthcare setting.