■评估麻疹暴发的风险并确定人群的易感部分对于及时干预至关重要。6-12个月之间的婴儿越来越容易受到麻疹的影响,但缺乏评估9个月以下婴儿的高通量酶免疫测定(ELISA)的性能。
■市售ELISA试剂盒(CreativeDiagnostics,DEIA359)用于评估5-7个月大的婴儿的麻疹血清保护。在2019年至2021年之间进行的丹麦MMR试验的免疫原性子研究中,在麻疹-腮腺炎-风疹疫苗(MMR)或安慰剂之前和之后一个月以及常规MMR之后一个月在15个月进行了婴儿(和基线的母亲)采样。通过Pearson和Spearman相关性并通过估计灵敏度,将麻疹IgGELISA与金标准但劳动密集型麻疹斑块减少中和试验(PRNT)进行了比较。特异性,以及阳性和阴性预测值(PPV和NPV)。
■与PRNT抗体相比,麻疹IgG水平的Pearson相关系数在0.10-0.24之间。通过ELISA测量的年轻婴儿的血清保护率比通过PRNT测量的低10-14%。与PRNT相比,ELISA在婴儿人群中检测血清学保护的敏感性在采样时间点显着不同,为14%,40%,基线时为92%,干预后,和后例程MMR,而特异性为99%,93%,43%,分别。基线时婴儿的PPV和NPV分别为68%和87%。
■麻疹IgG和PRNT抗体之间的相关性较低。使用ELISA低估了血清保护。需要进行高精度测试,以避免错误分类和做法,导致在爆发环境中主要或次要疫苗失败或疫苗保留。基线PPV和NPV表明ELISA在预测该年龄组的血清学保护方面具有一定的适用性。然而,PRNT可能是幼儿血清学保护的唯一准确估计器。
UNASSIGNED: Assessing the risk of measles outbreaks and identifying the susceptible parts of the population is essential to timely intervention. Infants between 6-12 months are increasingly susceptible to measles but evaluating the performance of high throughput enzyme immunoassays (ELISAs) in infants < 9 months of age is lacking.
UNASSIGNED: A commercially available ELISA kit (Creative Diagnostics, DEIA359) for estimating measles seroprotection was evaluated in infants 5-7 months of age. In an immunogenicity substudy in the Danish MMR trial conducted between 2019-2021, infants (and mothers at baseline) were sampled before and one month after measles-mumps-rubella vaccination (MMR) or placebo as well as one month after routine MMR at 15 months. Measles IgG ELISA was compared to the gold standard but labor-intensive measles plaque reduction neutralization test (PRNT) by Pearson and Spearman correlations and by estimating sensitivity, specificity, and positive and negative predictive values (PPV and NPV).
UNASSIGNED: Measles IgG levels compared to PRNT antibodies had a Pearson\'s correlation coefficient between 0.10-0.24. Seroprotection rates measured by ELISA in young infants were 10-14% lower than measured by PRNT. The sensitivity of the ELISA to detect serological protection compared to PRNT in the infant population differed markedly across sampling time points and was 14%, 40%, and 92% at baseline, post-intervention, and post-routine MMR, whereas the specificity was 99%, 93%, and 43%, respectively. The PPV and NPV were 68% and 87% in infants at baseline.
UNASSIGNED: The correlation between measles IgG and PRNT antibodies was low. Seroprotection was underestimated using ELISA. High-accuracy tests are needed to avoid misclassifications and practices that lead to primary or secondary vaccine failure or retention of vaccination in outbreak settings. Baseline PPV and NPV suggested some applicability of ELISA in predicting serological protection in this age group. However, PRNT may be the only accurate estimator of serological protection in young infants.