中国疫苗和免疫

目的 分析2019-2024年中国适龄儿童含无细胞百白破疫苗(Diphtheria,tetanus,and acellular pertussis vaccine,DTaP)成分联合疫苗接种现况。方法 通过中国免疫规划信息系统收集2019-2024年各省份≤2岁儿童含DTaP成分联合疫苗接种数据，分析≤2岁儿童接种剂次数的平均年度变化百分比(Average annual percentage change,AAPC)、对第1剂和第3剂DTaP替代率，以及2岁儿童第1剂、第1～3剂和第4剂接种比例。结果 中国≤2岁儿童含DTaP成分联合疫苗接种剂次数从2019年的698.62万剂次上升至2024年的912.46万剂次[AAPC(95%CI):5.49%(3.21%～7.82%)]，其中东部、中部、西部地区分别从355.06万、180.20万、163.36万剂次上升至474.37万、239.80万、199.29万剂次[AAPC(95%CI):5.45%(1.33%～9.74%)、5.49%(0.84%～12.23%)、4.33%(1.53%～7.20%)];对第1剂、第3剂DTaP替代率分别从2019年的12.49%、8.69%上升至2024年的27.59%、26.93%，其中东部地区分别从13.74%、9.92%上升至32.48%、31.96%，中部地区分别从11.95%、7.81%上升至29.00%、27.74%，西部地区分别从11.08%、7.67%上升至19.55%、19.21%。2岁儿童第1剂、第1～3剂和第4剂接种比例分别从2019年的8.85%、6.36%、5.14%上升至2024年的26.23%、24.70%、23.53%，其中东部地区分别从8.94%、5.90%、4.73%上升至31.04%、29.67%、28.69%，中部地区分别从9.42%、5.34%、3.86%上升至27.70%、25.15%、23.28%，西部地区分别从8.18%、4.82%、3.65%上升至18.47%、17.59%、16.76%。结论 2019-2024年中国≤2岁儿童含DTaP成分联合疫苗覆盖水平呈逐年上升趋势，但存在地区差异。

Objective To analyze and describe the status of vaccination with diphtheria,tetanus,and acellular pertussis vaccine( DTaP)-containing combination vaccines in children aged ≤2 years in China from 2019 to 2024. Methods We obtained data on vaccination with DTaP-containing combination vaccines administered to ≤2-year-olds during 2019-2024 in all provinces from the National Immunization Program Information System. We calculated the average annual percentage change( AAPC) of doses administered,rates of substitution of DTaP with DTaP-containing combination vaccines for the first and third DTaP doses,and coverage levels of the first,the first-to-third,and the fourth dose of DTaPcontaining combination vaccines. Results The number of DTaP-containing combination vaccine doses administered to ≤2-year-olds in China increased from 6.986 2 million in 2019 to 9.124 6 million in 2024[AAPC( 95% CI) : 5.49%( 3.21%-7.82%) ]. By region,the numbers of doses administered increased from 3.550 6,1.802 0,and 1.633 6 million to 4.743 7,2.398 0,and 1.992 9 million in eastern,central,and western regions,respectively [AAPC( 95% CI) : 5.45%( 1.33%-9.74%),5.49%( 0.84%-12.23%),and 4.33%( 1.53%-7.20%) ]. Substitution rates for the first and third doses increased from 12.49% and 8.69% in2019 to 27.59% and 26.93% in 2024. By region,the respective rates increased from 13.74% and 9.92%to 32.48% and 31.96% in the eastern region,from 11.95% and 7.81% to 29.00% and 27.74% in the central region,and from 11. 08% and 7. 67% to 19. 55% and 19. 21% in the western region. Coverage levels of the first dose,the first-to-third doses,and the fourth dose increased from 8.85%,6.36%,and5.14% in 2019 to 26. 23%,24. 70%,and 23. 53% in 2024. By region,the respective coverage levels increased from 8.94%,5.90%,and 4.73% to 31.04%,29.67%,and 28.69% in the eastern region,from9.42%,5.34%,and 3.86% to 27.70%,25.15%,and 23.28% in the central region,and from 8.18%,4.82%,and 3.65% to 18.47%,17.59%,and 16.76% in the western region. Conclusion Coverage levels of DTaP-containing combination vaccines among children aged ≤2 years increased steadily from 2019 to2024 in China,with some regional variation.