Background England’s third trimester maternal pertussis vaccination, introduced in October 2012, was extended to the second trimester in 2016. Maternal vaccination provides high protection against infant disease but routine second trimester vaccination has not previously been assessed. Methods National laboratory-confirmed pertussis case-surveillance determined vaccination history, maternal vaccination history and hospitalisation. Pertussis hospital admissions between 2012-2019 were extracted from the Hospital Episode Statistics dataset. Vaccine effectiveness (VE) was calculated for pertussis cases born between October 2012 and September 2018 using the screening method and matching with a nationally representative dataset. Results Higher coverage was observed after earlier maternal vaccination with approximately 40% of pregnant women vaccinated ≥13 weeks before delivery. Cases and hospitalisations stabilised at low levels in younger infants but remained elevated in older infants, children and adults. No deaths arose in infants with vaccinated mothers after 2016. Of 1162 laboratory-confirmed pertussis cases in the study, 599 (52%) were aged <93 days: 463 (77%) with unvaccinated mothers and 136 (23%) with vaccinated. Vaccine effectiveness was equivalent in infants with mothers vaccinated at different gestational periods excepting infants with mothers vaccinated between 7-days pre- and 41-days post-delivery. Children whose mothers were unvaccinated but with vaccination in a previous pregnancy had a VE against disease of 44% (19% to 75%). There was no increased disease risk after primary vaccination in children with mothers vaccinated at least 7 days before delivery. Conclusions National policy recommending vaccination from second trimester increased earlier maternal vaccine uptake with sustained high effectiveness and impact against early infant disease.

中文翻译：

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从英格兰实施后 6 年的监测数据优化孕妇百日咳免疫接种时间

背景 英格兰于 2012 年 10 月推出的孕晚期孕妇百日咳疫苗接种于 2016 年延长至孕中期。孕产妇接种疫苗可针对婴儿疾病提供高度保护，但之前未对常规孕中期疫苗接种进行过评估。方法国家实验室确诊的百日咳病例监测确定疫苗接种史、母体疫苗接种史和住院情况。从 Hospital Episode Statistics 数据集中提取了 2012-2019 年的百日咳住院情况。使用筛选方法并与具有全国代表性的数据集相匹配，计算了 2012 年 10 月至 2018 年 9 月期间出生的百日咳病例的疫苗有效性 (VE)。结果 大约 40% 的孕妇在分娩前 ≥ 13 周接种疫苗后，早期接种疫苗后观察到更高的覆盖率。年幼婴儿的病例数和住院率稳定在较低水平，但年长婴儿、儿童和成人的病例和住院率仍然较高。2016 年之后，母亲接种疫苗的婴儿没有死亡。在研究中的 1162 例实验室确诊的百日咳病例中，599 例 (52%) 的年龄小于 93 天：463 例 (77%) 的母亲未接种疫苗，136 例 (23%) 的母亲接种了疫苗. 除了母亲在分娩前 7 天和分娩后 41 天之间接种疫苗的婴儿外，疫苗效力在母亲在不同妊娠期接种疫苗的婴儿中是相同的。母亲未接种疫苗但在之前怀孕时接种过疫苗的儿童的 VE 为 44%（19% 至 75%）。母亲在分娩前至少 7 天接种疫苗的儿童在初次接种疫苗后并未增加疾病风险。结论 建议从妊娠中期开始接种疫苗的国家政策提高了母体疫苗的早期接种率，具有持续的高效性和对早期婴儿疾病的影响。