Division of Viral Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, USA.
Clin Infect Dis. 2021 Jan 27;72(2):222-229. doi: 10.1093/cid/ciaa019.
Norovirus is a leading cause of acute gastroenteritis worldwide, yet there is limited information on homotypic or heterotypic protection following natural infection to guide vaccine development.
A total of 6020 stools collected from 299 Peruvian children between 2010 and 2014 were tested by norovirus real-time reverse-transcription polymerase chain reaction followed by sequence-based genotyping. Cox proportional hazards models were used to derive adjusted hazard ratios (HRs) of infection among children with vs without prior exposure.
Norovirus was detected in 1288 (21.3%) samples. GII.4 (26%), GII.6 (19%), and GI.3 (9%) viruses accounted for 54% of infections. Homotypic protection for GI.3 (HR, 0.35; P = .015), GI.7 (HR, 0.19; P = .022), GII.4 (HR, 0.39; P < .001), and GII.6 (HR, 0.52; P = .006) infections was observed. Hazard analysis showed that children with prior GII.4 infection exhibited heterotypic protection with a 48% reduction of subsequent GI.3 infection (HR, 0.52; P = .005). Prior exposure to GI.3, GII.2, and GII.17 infections enhanced susceptibility to subsequent infections with several other norovirus genotypes.
Children up to 2 years of age infected with GII.4 noroviruses demonstrated both homotypic and heterotypic protection to reinfection with other genotypes. These data support the need for ongoing vaccine development efforts with GII.4 as the main component and caution the inclusion of genotypes that may enhance susceptibility to infections.
诺如病毒是全世界急性肠胃炎的主要病因，但对于自然感染后的同型或异型保护知之甚少，无法据此指导疫苗开发。
我们对 2010 年至 2014 年间采集的来自秘鲁 299 名儿童的 6020 份粪便标本进行了诺如病毒实时逆转录聚合酶链反应检测，并进行了基于序列的基因分型。采用 Cox 比例风险模型得出了有和无既往暴露的儿童中感染的校正风险比（HR）。
在 1288 份（21.3%）样本中检测到了诺如病毒。GII.4（26%）、GII.6（19%）和 GI.3（9%）病毒占所有感染的 54%。观察到 GI.3（HR，0.35；P=0.015）、GI.7（HR，0.19；P=0.022）、GII.4（HR，0.39；P<0.001）和 GII.6（HR，0.52；P=0.006）感染的同型保护。危险度分析表明，既往感染 GII.4 的儿童发生后续 GI.3 感染的风险降低了 48%（HR，0.52；P=0.005）。既往感染 GI.3、GII.2 和 GII.17 会增加随后感染其他诺如病毒基因型的易感性。
2 岁以下感染 GII.4 诺如病毒的儿童对其他基因型的再感染表现出同型和异型保护。这些数据支持继续开展以 GII.4 为主要成分的疫苗开发工作，并告诫要注意包括可能增加感染易感性的基因型。
