Safety evaluation of inactivated poliomyelitis vaccine

This study aimed to evaluate the safety profile of inactivated poliomyelitis vaccine made from Sabin strains (sIPV) developed by the Institute of Medical Biology, Chinese Academy of Medical Sciences, during its post-marketing real-world use in China from 2015 to 2025. A database-based retrospective analysis was conducted using multi-source data, including the Chinese Center for Disease Control and Prevention's (CDC) Adverse Events Following Immunization (AEFI) surveillance system, post-marketing safety studies, and internal vaccination databases. Safety metrics were compared with national IPV (2018-2022) and all marketed vaccines. Statistical analyses employed chi-square and Fisher's exact tests. Among 50,111,746 sIPV doses administered, 12,788 AEFI cases were reported (25.52 per 100,000 doses). sIPV exhibited significantly lower AEFI reported incidences than national IPV data for pyrexia (≥38.6°C) (6.19 vs. 8.51 per 100,000 doses, P < .001), vaccination site erythema/swelling (>2.5 cm) (3.46 vs. 3.85 per 100,000 doses, P < .001), and vaccination site induration (>2.5 cm) (0.90 vs. 1.19 per 100,000 doses, P < .001). The incidence of severe AEFI (0.13 per 100,000 doses) was significantly different (P < .001) from that of the national IPV. Most AEFI (97.41%) occurred within 3 d post-vaccination, and 71.31% resolved completely. sIPV demonstrates an excellent safety profile, supporting its role in polio eradication. Continued monitoring is essential for rare events and regional disparities.