Prospective, Multi-center Post-marketing Surveillance Cohort Study to Monitor the Safety of the Human Papillomavirus-16/18 AS04-adjuvanted Vaccine in Chinese Girls and Women Aged 9 to 45 Years, 2018-2020

Following the approval of for the immunization of girls and women in China against high-risk human papillomavirus types 16 and 18, a non-interventional post-authorization safety study was performed. A multi-center prospective cohort study assessed safety following vaccination of Chinese girls and women aged 9-45 years between 31 May 2018 and 3 December 2020. Adverse events following immunization (AEFIs), potential immune-mediated diseases (pIMDs), and pregnancy-related outcomes were collected up to 12 months from the third immunization or 24 months from the first immunization, whichever came first. Among 3,013 women who received 8,839 doses, 167 (5.5%) reported ≥ 1 any AEFI, and 22 (0.7%) reported 40 serious AEFIs. During the 30 days after each dose, 147 women (4.9%) reported 211 medically attended AEFIs, including 3 serious AEFIs reported by 1 woman (0.03%). One woman reported a pIMD. was inadvertently administered to 65 women (2.2%) within 60 days before conception or during pregnancy. Of these women, 34 (52.3%) gave birth to live infant(s) with no apparent congenital anomalies, and 1 (1.5%) woman gave birth to a live infant with a congenital anomaly. No serious AEFIs or pIMDs were considered to be related to the vaccination. In Chinese women aged 9-45 years, immunization with the three-dose schedule was well tolerated. Overall, no safety concerns were identified, although rare adverse events may have been missed due to the study sample size.Clinical trial registration: NCT03438006.