肯尼亚母亲移民到非正式城市住区后儿童疫苗接种的及时性。

Department of Epidemiology, School of Public Health, University of Michigan, USA; Global Institute for Vaccine Equity, University of Michigan, USA.

Vaccine. 2022 Jan 28;40(4):627-639. doi: 10.1016/j.vaccine.2021.12.017. Epub 2021 Dec 21.

INTRODUCTION

Timely receipt of recommended vaccines is a proven strategy to reduce preventable under-five deaths. Kenya has experienced impressive declines in child mortality from 111 to 43 deaths per 1000 live births between 1980 and 2019. However, considerable inequities in timely vaccination remain, which unnecessarily increases risk for serious illness and death. Maternal migration is a potentially important driver of timeliness inequities, as the social and financial stressors of moving to a new community may require a woman to delay her child's immunizations. This analysis examined how maternal migration to informal urban settlements in Nairobi, Kenya influenced childhood vaccination timeliness.

METHODS

Data came from the Nairobi Urban Health and Demographic Surveillance System, 2002-2018. Migration exposures were migrant status (migrant, non-migrant), migrant origin (rural, urban), and migrant type (first-time, circular [previously resided in settlement]). Age at vaccine receipt (vaccination timeliness) was calculated for all basic vaccinations. Accelerated failure time models were used to investigate relationships between migration exposures and vaccination timeliness. Confounding was addressed using propensity score weighting.

RESULTS

Over one-third of the children of both migrants and non-migrants received at least one dose late or not at all. Unweighted models showed the children of migrants had shorter time to OPV1 and DPT1 vaccine receipt compared to the children of non-migrants. After accounting for confounding only differences in timeliness for DPT1 remained, with the children of migrants receiving DPT1 significantly earlier than the children of non-migrants. Timeliness was comparable among migrants with rural and urban origins and among first-time and circular migrants.

CONCLUSION

Although a substantial proportion of children in Nairobi's informal urban settlements do not receive timely vaccination, this analysis found limited evidence that maternal migration and migration characteristics were associated with delays for most doses. Future research should seek to elucidate potential drivers of low vaccination timeliness in Kenya.

简介

及时接种推荐疫苗是减少 5 岁以下儿童死亡的一种已被证实的策略。肯尼亚在 1980 年至 2019 年期间经历了儿童死亡率从每 1000 例活产 111 例降至 43 例的显著下降。然而，及时接种疫苗方面仍然存在相当大的不平等，这不必要地增加了患病和死亡的风险。产妇迁移是造成及时性不平等的一个潜在重要因素，因为迁移到新社区带来的社会和经济压力可能要求妇女推迟其子女的免疫接种。本分析研究了肯尼亚内罗毕非正式城市住区的产妇迁移如何影响儿童疫苗接种的及时性。

方法

数据来自内罗毕城市健康和人口监测系统，2002-2018 年。迁移暴露包括迁移状况（移民、非移民）、移民原籍（农村、城市）和移民类型（首次、循环[以前居住在定居点]）。所有基础疫苗的接种年龄（疫苗接种及时性）均进行计算。使用加速失效时间模型来研究迁移暴露与疫苗接种及时性之间的关系。使用倾向评分加权来解决混杂问题。

结果

移民和非移民的子女中，有三分之一以上的人至少有一剂疫苗接种延迟或根本未接种。未加权模型显示，与非移民的子女相比，移民的子女在接受 OPV1 和 DPT1 疫苗接种方面的时间更短。在考虑到混杂因素后，仅 DPT1 的及时性差异仍然存在，移民的子女比非移民的子女更早接受 DPT1 疫苗接种。农村和城市原籍的移民以及首次和循环移民之间的及时性相当。