Post-marketing surveillance of adverse events following enterovirus type 71 inactivated vaccine in China, 2016-2023.

OBJECTIVE

To assess adverse events following immunization (AEFI) for Enterovirus type 71 (EV71) vaccines in the mainland of China during a post-market-authorization period.

METHODS

We obtained AEFI reports for EV71 vaccine during 2016-2023 from the Chinese National Immunization Information System (CNIIS). We obtained EV71 vaccine doses administered data for 2016-2018 and 2019-2023 from provincial immunization information systems or vaccination doctors' reports and from CNIIS, respectively. We analyzed all EV71 vaccine AEFI reports.

RESULTS

During the study period, there were 100.95 million doses of EV71 vaccine administered and 41,025 AEFI reports following EV71 vaccination. Incidences of EV71 AEFI reports for any reason, serious AEFI, common vaccine reactions (usually minor), and rare vaccine reactions (possibly serious) were 40.64, 0.30, 36.55, and 2.78 reports per 100,000 doses administered. The most frequently reported common vaccine reaction was fever; allergic rash was the main reported rare vaccine reaction; respective incidences were 30.28 and 2.43 per 100,000 doses.

CONCLUSIONS

A favorable safety profile of EV71 vaccine was confirmed. EV71 vaccine can be used safely to prevent EV71-related diseases in children under 5 years old.