Real-world safety profile of the diphtheria, tetanus, and acellular pertussis combined vaccine: A study in Huzhou from 2020 to 2024

This study aimed to evaluate the safety profile of the diphtheria, tetanus, and acellular pertussis combined vaccine (DTaP) based on real-world data from 2020 to 2024 in Huzhou city and provided data support for the adjustment of DTaP immunization strategy. The data of adverse events following immunization (AEFI) and vaccination information were collected from National Adverse Event Following Immunization Surveillance System (NAEFISS) in Huzhou city from 2020 to 2024 for a descriptive epidemiological analysis. This study used the reporting odds ratio (ROR) was for anomalous signal assessment. A total of 483 AEFI of DTaP vaccine were reported in Huzhou city from 2020 to 2024, the reported rate of AEFI was 15.87/10,000 doses. The reporting rate of AEFI showed an increasing trend from 2020 to 2024 (Z = 2.314, P = .021). There was no significant changes in the reporting rates of rare vaccine reactions (Z = -0.943, P = .346). There were 7 cases of allergic rash (0.23/10,000 doses), 1 case of urticaria (0.03/10,000 doses), 1 case of angioedema (0.03/10,000 doses). The most common AEFI reported was redness with 373 cases (12.25/10,000 doses), followed by induration (213 case, 7.00/10,000 doses). A positive signal association between DTaP and adverse events such as redness (ROR-1.96SE: 2.56) (standard error [SE]), induration (ROR-1.96SE: 2.07) and crying (ROR-1.96SE: 1.15) was found. The present findings supported that the DTaP vaccine was generally well tolerated as this study did not identify any new/unexpected safety concern during a 5-year time period.