Department of Pediatrics, All India Institute of Medical sciences, New Delhi, 110029, India.
ICGEB-Emory Vaccine Center, International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
Arch Virol. 2021 Jul;166(7):1913-1920. doi: 10.1007/s00705-021-05049-3. Epub 2021 Apr 27.
Chikungunya virus (CHIKV) infection is endemic in many different countries. CHIKV outbreaks are emerging in new areas and re-emerging in previously exposed geographical regions, thus making it a significant public health concern. CHIKV infections are often clinically inapparent, especially in children, which poses a challenge to testing and evaluating any vaccine. During CHIKV infection, CHIKV-specific antibodies are produced, and some of these antibodies can neutralize viruses released from infected cells before they can enter uninfected cells. In this study, we evaluated IgG binding and neutralizing antibody responses in paired serum samples from CHIKV-infected children and those with other febrile illness, using a recombinant truncated E2 protein and whole CHIKV particles as test antigens. Antibody detection using the truncated E2 protein showed a significant overlap between CHIKV-infected subjects and those with other febrile illnesses. This overlap was greater when binding antibody titers were determined using fixed CHIKV particles as the test antigen. Acute- and convalescent-phase sera collected from children after CHIKV infection showed significant differences in their neutralizing capacity. The neutralizing and binding antibody response showed a significant positive correlation. We detected IgG antibodies in most cases during the acute phase of infection. This was observed at two different geographical locations, one of which is not considered highly endemic. Conventional wisdom would suggest this to be a marker of re-infection (secondary infection). However, dissenting opinions have been voiced in other viral diseases (such as Ebola) where studies have detected IgG in acute illness. In the absence of any significant body of work documenting secondary CHIKV infections, we believe further work is needed to understand the early IgG response that we observed.
基孔肯雅热病毒（CHIKV）感染在许多不同的国家流行。CHIKV 暴发在新的地区出现，并在以前暴露的地理区域重新出现，因此成为一个重大的公共卫生关注点。CHIKV 感染通常在临床上无明显症状，尤其是在儿童中，这给检测和评估任何疫苗带来了挑战。在 CHIKV 感染期间，会产生 CHIKV 特异性抗体，其中一些抗体可以在感染细胞释放的病毒进入未感染细胞之前中和它们。在这项研究中，我们使用重组截短 E2 蛋白和完整 CHIKV 颗粒作为测试抗原，评估了来自 CHIKV 感染儿童和其他发热性疾病患者的配对血清样本中的 IgG 结合和中和抗体反应。使用截短 E2 蛋白检测抗体显示，CHIKV 感染患者与其他发热性疾病患者之间存在显著重叠。当使用固定的 CHIKV 颗粒作为测试抗原确定结合抗体滴度时，这种重叠更大。从 CHIKV 感染后儿童采集的急性期和恢复期血清显示出其中和能力的显著差异。中和和结合抗体反应呈显著正相关。我们在感染后的急性期中检测到大多数病例中的 IgG 抗体。这在两个不同的地理位置都观察到，其中一个地理位置不被认为是高度流行的。传统观点认为这是再感染（二次感染）的标志。然而，在其他病毒性疾病（如埃博拉）中，也有不同的观点，这些研究在急性疾病中检测到了 IgG。在没有任何大量的工作来记录二次 CHIKV 感染的情况下，我们认为需要进一步的工作来了解我们观察到的早期 IgG 反应。
