PDF(Pubmed)
Abstract：
Routine childhood immunisation is one of the most important life-saving public health interventions. However, many children still have inadequate access to these vaccines and millions remain (partially) unvaccinated globally. As the COVID-19 pandemic disrupted health systems worldwide, its effects on immunisation have become apparent. This study aimed to estimate routine immunisation coverage among children under two in Sierra Leone and to identify factors associated with incomplete immunisation during the COVID-19 pandemic.
A cross-sectional household survey was conducted in three districts in Sierra Leone: Bombali, Tonkolili and Port Loko. A three-stage cluster sampling method was followed to enrol children aged 10-23 months. Information regarding immunisation status was based on vaccination cards or caretaker\'s recall. Using WHO\'s definition, a fully immunised child received one BCG dose, three oral polio vaccine doses, three pentavalent vaccine doses and one measles-containing vaccine dose. Following the national schedule, full immunisation status can be achieved at 9 months of age. Data were weighted to reflect the survey\'s sampling design. Associations between incomplete immunisation and sociodemographic characteristics were assessed through multivariable logistic regression.
A total of 720 children were enrolled between November and December 2021. Full vaccination coverage was estimated at 65.8% (95% CI 60.3%-71.0%). Coverage estimates were highest for vaccines administered at birth and decreased with doses administered subsequently. Adjusting for age, the lowest estimated coverage was 40.7% (95% CI 34.5%-47.2%) for the second dose of the measles-containing vaccine. Factors found to be associated with incomplete immunisation status were: living in Port Loko district (aOR = 3.47, 95% CI = 2.00-6.06; p-value < 0.001), the interviewed caretaker being Muslim (aOR = 1.94, 95% CI = 1.25-3.02; p-value = 0.015) and the interviewed caretaker being male (aOR = 1.93, 95% CI = 1.03-3.59, p-value = 0.039).
Though full immunisation coverage at district level improved compared with pre-pandemic district estimates from 2019, around one in three surveyed children had missed at least one basic routine vaccination and over half of eligible children had not received the recommended two doses of a measles-containing vaccine. These findings highlight the need to strengthen health systems to improve vaccination uptake in Sierra Leone, and to further explore barriers that may jeopardise equitable access to these life-saving interventions.
A cross-sectional household survey was conducted in three districts in Sierra Leone: Bombali, Tonkolili and Port Loko. A three-stage cluster sampling method was followed to enrol children aged 10-23 months. Information regarding immunisation status was based on vaccination cards or caretaker\'s recall. Using WHO\'s definition, a fully immunised child received one BCG dose, three oral polio vaccine doses, three pentavalent vaccine doses and one measles-containing vaccine dose. Following the national schedule, full immunisation status can be achieved at 9 months of age. Data were weighted to reflect the survey\'s sampling design. Associations between incomplete immunisation and sociodemographic characteristics were assessed through multivariable logistic regression.
A total of 720 children were enrolled between November and December 2021. Full vaccination coverage was estimated at 65.8% (95% CI 60.3%-71.0%). Coverage estimates were highest for vaccines administered at birth and decreased with doses administered subsequently. Adjusting for age, the lowest estimated coverage was 40.7% (95% CI 34.5%-47.2%) for the second dose of the measles-containing vaccine. Factors found to be associated with incomplete immunisation status were: living in Port Loko district (aOR = 3.47, 95% CI = 2.00-6.06; p-value < 0.001), the interviewed caretaker being Muslim (aOR = 1.94, 95% CI = 1.25-3.02; p-value = 0.015) and the interviewed caretaker being male (aOR = 1.93, 95% CI = 1.03-3.59, p-value = 0.039).
Though full immunisation coverage at district level improved compared with pre-pandemic district estimates from 2019, around one in three surveyed children had missed at least one basic routine vaccination and over half of eligible children had not received the recommended two doses of a measles-containing vaccine. These findings highlight the need to strengthen health systems to improve vaccination uptake in Sierra Leone, and to further explore barriers that may jeopardise equitable access to these life-saving interventions.
摘要：
背景：儿童常规免疫接种是最重要的挽救生命的公共卫生干预措施之一。然而,许多儿童仍然无法获得这些疫苗，全球仍有数百万人(部分)未接种疫苗。随着COVID-19大流行破坏了全球卫生系统，它对免疫接种的影响已经变得显而易见。这项研究旨在评估塞拉利昂两岁以下儿童的常规免疫覆盖率，并确定与COVID-19大流行期间免疫不完全相关的因素。
方法：在塞拉利昂的三个地区进行了横断面家庭调查：Bombali，Tonkolili和PortLoko.采用三阶段整群抽样方法对10-23个月的儿童进行登记。有关免疫接种状态的信息基于疫苗接种卡或看护者的召回。使用WHO的定义，一名完全免疫的儿童接受了一次卡介苗，三剂口服脊髓灰质炎疫苗，三剂五价疫苗和一剂含麻疹疫苗。按照国家时间表，完全免疫状态可以在9个月大时实现。对数据进行加权，以反映调查的抽样设计。通过多变量逻辑回归评估不完全免疫与社会人口统计学特征之间的关联。
结果：在2021年11月至12月期间，共有720名儿童入学。全疫苗接种覆盖率估计为65.8%（95%CI60.3%-71.0%）。出生时接种疫苗的覆盖率估计最高，随着随后接种的剂量下降。调整年龄，第二剂含麻疹疫苗的最低估计覆盖率为40.7%(95%CI34.5%-47.2%).发现与不完全免疫状态相关的因素是：居住在PortLoko地区（aOR=3.47，95％CI=2.00-6.06；p值<0.001），受访看护者为穆斯林(aOR=1.94,95%CI=1.25-3.02;p值=0.015),受访看护者为男性(aOR=1.93,95%CI=1.03-3.59,p值=0.039)。
结论：尽管与2019年大流行前的地区估计相比，地区层面的全面免疫覆盖率有所提高，但约三分之一的受访儿童错过了至少一次基本常规疫苗接种，超过一半的合格儿童没有接受推荐的两剂含麻疹疫苗。这些发现强调了加强卫生系统以提高塞拉利昂疫苗接种率的必要性，并进一步探索可能危及公平获得这些救生干预措施的障碍。
方法：在塞拉利昂的三个地区进行了横断面家庭调查：Bombali，Tonkolili和PortLoko.采用三阶段整群抽样方法对10-23个月的儿童进行登记。有关免疫接种状态的信息基于疫苗接种卡或看护者的召回。使用WHO的定义，一名完全免疫的儿童接受了一次卡介苗，三剂口服脊髓灰质炎疫苗，三剂五价疫苗和一剂含麻疹疫苗。按照国家时间表，完全免疫状态可以在9个月大时实现。对数据进行加权，以反映调查的抽样设计。通过多变量逻辑回归评估不完全免疫与社会人口统计学特征之间的关联。
结果：在2021年11月至12月期间，共有720名儿童入学。全疫苗接种覆盖率估计为65.8%（95%CI60.3%-71.0%）。出生时接种疫苗的覆盖率估计最高，随着随后接种的剂量下降。调整年龄，第二剂含麻疹疫苗的最低估计覆盖率为40.7%(95%CI34.5%-47.2%).发现与不完全免疫状态相关的因素是：居住在PortLoko地区（aOR=3.47，95％CI=2.00-6.06；p值<0.001），受访看护者为穆斯林(aOR=1.94,95%CI=1.25-3.02;p值=0.015),受访看护者为男性(aOR=1.93,95%CI=1.03-3.59,p值=0.039)。
结论：尽管与2019年大流行前的地区估计相比，地区层面的全面免疫覆盖率有所提高，但约三分之一的受访儿童错过了至少一次基本常规疫苗接种，超过一半的合格儿童没有接受推荐的两剂含麻疹疫苗。这些发现强调了加强卫生系统以提高塞拉利昂疫苗接种率的必要性，并进一步探索可能危及公平获得这些救生干预措施的障碍。
