Kenya Medical Research Institute (KEMRI)-Wellcome Trust Research Programme, Centre for Geographic Medicine Research-Coast, P.O Box 230-80108, Kilifi, Kenya.
Kenya Medical Research Institute (KEMRI), Centre for Microbiology Research, Nairobi, Kenya.
BMC Public Health. 2020 Nov 16;20(1):1723. doi: 10.1186/s12889-020-09841-9.
Maternal immunisation to boost respiratory syncytial virus (RSV) specific antibodies in pregnant women is a strategy to enhance infant protection. The timing of maternal vaccination during pregnancy may be critical for its effectiveness. However, Kenya has no documented published data on gestational age distribution of pregnant women attending antenatal care (ANC), or the proportion of women attending ANC during the proposed window period for vaccination, to inform appropriate timing for delivery or estimate potential uptake of this vaccine.
A cross-sectional survey was conducted within the Kilifi Health and Demographic Surveillance System (KHDSS), coastal Kenya. A simple random sample of 1000 women who had registered pregnant in 2017 to 2018 and with a birth outcome by the time of data collection was taken. The selected women were followed at their homes, and individually written informed consent was obtained. Records of their antenatal attendance during pregnancy were abstracted from their ANC booklet. The proportion of all pregnant women from KHDSS (55%) who attended for one or more ANC in 2018 was used to estimate vaccine coverage.
Of the 1000 women selected, 935 were traced with 607/935 (64.9%) available for interview, among whom 470/607 (77.4%) had antenatal care booklets. The median maternal age during pregnancy was 28.6 years. The median (interquartile range) gestational age in weeks at the first to fifth ANC attendance was 26 (21-28), 29 (26-32), 32 (28-34), 34 (32-36) and 36 (34-38), respectively. The proportion of women attending for ANC during a gestational age window for vaccination of 28-32 weeks (recommended), 26-33 weeks and 24-36 weeks was 76.6% (360/470), 84.5% (397/470) and 96.2% (452/470), respectively. Estimated vaccine coverage was 42.1, 46.5 and 52.9% within the narrow, wide and wider gestational age windows, respectively.
In a random sample of pregnant women from Kilifi HDSS, Coastal Kenya with card-confirmed ANC clinic attendance, 76.6% would be reached for maternal RSV vaccination within the gestational age window of 28-32 weeks. Widening the vaccination window (26-33 weeks) or (24-36 weeks) would not dramatically increase vaccine coverage and would require consideration of antibody kinetics data that could affect vaccine efficacy.
在孕妇中进行母体免疫接种以增强呼吸道合胞病毒（RSV）特异性抗体是增强婴儿保护的一种策略。母体疫苗接种在怀孕期间的时间可能对其有效性至关重要。然而，肯尼亚没有关于参加产前保健（ANC）的孕妇的妊娠年龄分布或建议接种疫苗窗口期内参加 ANC 的妇女比例的记录，以告知适当的分娩时间或估计这种疫苗的潜在接种率。
在肯尼亚沿海基利菲健康和人口监测系统（KHDSS）内进行了一项横断面调查。从 2017 年至 2018 年登记怀孕并在数据收集时已有分娩结果的 1000 名妇女中抽取了简单随机样本。对选定的妇女进行家访，并获得了他们的个人书面知情同意。从他们的 ANC 手册中摘录了他们怀孕期间接受产前护理的记录。利用 KHDSS（55%）中所有孕妇中有一人或多人在 2018 年接受 ANC 的比例来估计疫苗覆盖率。
在所选择的 1000 名妇女中，有 935 名被追踪到，其中有 607 名/935 名（64.9%）可接受访谈，其中 470 名/607 名（77.4%）有 ANC 手册。怀孕期间孕妇的平均年龄为 28.6 岁。第一次到第五次 ANC 就诊时的中位数（四分位距）孕周分别为 26（21-28）、29（26-32）、32（28-34）、34（32-36）和 36（34-38）。在推荐的 28-32 周（推荐）、26-33 周和 24-36 周的妊娠龄窗内接受 ANC 的妇女比例分别为 76.6%（360/470）、84.5%（397/470）和 96.2%（452/470）。在狭义、广义和更广泛的妊娠龄窗内，估计疫苗接种率分别为 42.1%、46.5%和 52.9%。
在肯尼亚沿海基利菲健康和人口监测系统的随机抽样孕妇中，在 28-32 周的妊娠龄窗内，将有 76.6%的孕妇可接受 RSV 母源疫苗接种。扩大疫苗接种窗口（26-33 周）或（24-36 周）不会显著增加疫苗覆盖率，并且需要考虑可能影响疫苗效力的抗体动力学数据。
