From the Department of Family Medicine, University of North Carolina, Chapel Hill, NC.
Center of Infectious Diseases, Department of Microbiology and Parasitology, Faculty of Medical Sciences, National Autonomous University of Nicaragua-León, León, Nicaragua.
Epidemiology. 2022 Sep 1;33(5):650-653. doi: 10.1097/EDE.0000000000001500. Epub 2022 Jun 10.
Norovirus and sapovirus cause a large burden of acute gastroenteritis (AGE) in young children. We assessed protection conferred by norovirus and sapovirus AGE episodes against future episodes.
Between June 2017 and July 2018, we recruited 444 newborns in León, Nicaragua. Weekly household surveys identified AGE episodes over 36 months, and AGE stools were tested by reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) for norovirus genogroup (G)I/GII and sapovirus. We used recurrent-event Cox models and negative control methods to estimate protection conferred by first episodes, controlling for observed and unobserved risk factors, respectively.
Sapovirus episodes conferred a 69% reduced hazard of subsequent episodes using the negative control method. Norovirus GI (hazard ratio [HR] = 0.67; 95% confidence interval [CI] = 0.31, 1.3) and GII (HR = 0.20; 95% CI = 0.04, 0.44) episodes also appeared highly protective. Protection against norovirus GII was enhanced following two episodes.
Evidence of natural immunity in early childhood provides optimism for the future success of pediatric norovirus and sapovirus vaccines.
诺如病毒和星状病毒可导致婴幼儿发生大量急性胃肠炎（AGE）。我们评估了诺如病毒和星状病毒 AGE 发作对未来发作的保护作用。
2017 年 6 月至 2018 年 7 月，我们在尼加拉瓜莱昂招募了 444 名新生儿。每周的家庭调查确定了 36 个月内的 AGE 发作，并用逆转录-定量聚合酶链反应（RT-qPCR）检测 AGE 粪便中的诺如病毒属（G）I/GII 和星状病毒。我们使用复发性事件 Cox 模型和阴性对照方法分别估计首次发作和观察到的和未观察到的危险因素所赋予的保护作用。
阴性对照方法显示，星状病毒发作可降低后续发作的危险 69%。诺如病毒 GI（危险比[HR] = 0.67；95%置信区间[CI] = 0.31, 1.3）和 GII（HR = 0.20；95% CI = 0.04, 0.44）发作也具有高度保护作用。两次发作后，对诺如病毒 GII 的保护作用增强。
在儿童早期存在自然免疫的证据为儿科诺如病毒和星状病毒疫苗的未来成功提供了乐观的前景。
