Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA 90095, United States.
David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, United States.
Vaccine. 2020 Feb 24;38(9):2258-2265. doi: 10.1016/j.vaccine.2019.09.047.
Measles is endemic in the Democratic Republic of the Congo (DRC), and 89-94% herd immunity is required to halt its transmission. Much of the World Health Organization African Region, including the DRC, has vaccination coverage below the 95% level required to eliminate measles, heightening concern of inadequate measles immunity.
We assessed 6706 children aged 6-59 months whose mothers were selected for interview in the 2013-2014 DRC Demographic and Health Survey. History of measles was obtained by maternal report, and classification of children who had measles was completed using maternal recall and measles immunoglobulin G serostatus obtained from a multiplex chemiluminescent automated immunoassay dried blood spot analysis. A logistic regression model was used to identify associations of covariates with measles and seroprotection, and vaccine effectiveness (VE) was calculated.
Out of our sample, 64% of children were seroprotected. Measles vaccination was associated with protection against measles (OR: 0.15, 95% CI: 0.03, 0.81) when administered to children 12 months of age or older. Vaccination was predictive of seroprotection at all ages. VE was highest (88%) among children 12-24 months of age.
Our results demonstrated lower than expected seroprotection against measles among vaccinated children. Understanding the factors that affect host immunity to measles will aid in developing more efficient and effective immunization programs in DRC.
麻疹在刚果民主共和国（DRC）流行，需要 89-94%的人群免疫率才能阻断其传播。世界卫生组织非洲区域的大部分地区，包括 DRC，疫苗接种覆盖率低于消除麻疹所需的 95%，这加剧了对麻疹免疫不足的担忧。
我们评估了 6706 名年龄在 6-59 个月之间的儿童，其母亲在 2013-2014 年刚果民主共和国人口与健康调查中被选中接受访谈。麻疹病史由母亲报告获得，通过母亲回忆和从多重化学发光自动化免疫分析干血斑分析中获得的麻疹免疫球蛋白 G 血清阳性状态来确定有麻疹的儿童的分类。使用逻辑回归模型来确定协变量与麻疹和血清保护的关联，并计算疫苗效力（VE）。
在我们的样本中，64%的儿童具有血清保护力。麻疹疫苗接种与 12 个月或以上儿童的麻疹保护作用相关（OR：0.15，95%CI：0.03，0.81）。疫苗接种在所有年龄段都预测具有血清保护力。VE 在 12-24 个月的儿童中最高（88%）。
我们的结果表明，接种疫苗的儿童对麻疹的血清保护力低于预期。了解影响宿主对麻疹免疫力的因素将有助于在 DRC 制定更有效和有效的免疫计划。
