Muhsen Khitam, Choi Yoon Hong, Walker Jemma, Andrews Nick, McDonald Helen I, Brown Kevin, Miller Elizabeth
Department of Epidemiology and Preventive Medicine, School of Public Health, Gray Faculty of Medical and Health Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv, 6139001, Israel.
London School of Hygiene and Tropical Medicine, London, UK.
Infection. 2025 Aug 28. doi: 10.1007/s15010-025-02630-9.
Measles outbreaks have occurred across England since mid-2023. We estimated measles and rubella antibody seroprevalence among individuals in 2018 in English regions outside London, and estimated the effective reproduction number (Re) for measles to predict the potential for outbreaks.
Using validated enzyme-linked immunosorbent assays, anti-Measles and anti-Rubella IgG antibodies were measured in residual sera from 3758 1-30-year-olds born after introduction of measles-mumps-rubella vaccination who submitted samples to clinical laboratories outside London. The measles Re was calculated using seronegatives defined by the manufacturer's cutoff, mixture modelling, and vaccination coverage data.
Using the manufacturer's cutoffs, the overall proportion seronegative to measles was 9.2% (95% confidence interval 8.3-10.1), and 10.3% (9.4-11.3) had equivocal results. The respective estimates for rubella were lower at 5.2% (4.6-6.0) and 5.4% (4.7-6.1). For both viruses, equivocal proportions increased with age, consistent with antibody waning. Mixture modelling for measles identified a common seronegative distribution across age groups, with lower proportions seronegative than using the manufacturer's cutoff. Re for measles using the manufacturer's seronegative cutoff (~ 150 mille international units/mL) was 1.00, versus 0.38 and 0.51 using the mixture model and vaccination coverage, respectively.
Re for measles estimated from seroepidemiology using an antibody cut-off similar to that considered a correlate of protection for measles was a more accurate predictor of recent measles resurgences outside London than those estimated using mixture modelling of seronegatives or coverage data. Seroepidemiological studies are a useful adjunct to coverage data in monitoring population immunity and in predicting the potential for measles outbreaks.
自2023年年中以来，英格兰各地均有麻疹疫情爆发。我们估算了2018年伦敦以外英国各地区人群的麻疹和风疹抗体血清阳性率，并估算了麻疹的有效繁殖数（Re）以预测疫情爆发的可能性。
采用经过验证的酶联免疫吸附测定法，对3758名1至30岁、在麻疹-腮腺炎-风疹疫苗接种引入后出生且向伦敦以外临床实验室提交样本的人群的残留血清进行抗麻疹和抗风疹IgG抗体检测。麻疹的Re使用制造商设定的临界值、混合模型和疫苗接种覆盖率数据所定义的血清阴性者来计算。
按照制造商的临界值，麻疹血清阴性的总体比例为9.2%（95%置信区间8.3 - 10.1），结果不明确的比例为10.3%（9.4 - 11.3）。风疹的相应估算值较低，分别为5.2%（4.6 - 6.0）和5.4%（4.7 - 6.1）。对于这两种病毒，结果不明确的比例均随年龄增加，这与抗体衰减一致。麻疹的混合模型确定了各年龄组中常见的血清阴性分布，血清阴性比例低于使用制造商临界值时的情况。使用制造商血清阴性临界值（约150毫国际单位/毫升）计算的麻疹Re为1.00，而使用混合模型和疫苗接种覆盖率计算的结果分别为0.38和0.51。
与使用血清阴性者的混合模型或覆盖率数据估算的结果相比，利用与被视为麻疹保护相关指标类似的抗体临界值通过血清流行病学估算的麻疹Re，能更准确地预测伦敦以外地区近期麻疹疫情的复发情况。血清流行病学研究是监测人群免疫力和预测麻疹疫情爆发可能性时覆盖率数据的有用补充。
