Respiratory syncytial virus (RSV)-specific serum antibody has been correlated to protection of infection and reduction of severe disease, but reinfection is still frequent. In this study, we evaluated RSV-specific serum antibody activity following natural RSV re-infection to examine the longevity of the humoral immune response in adults. Nineteen healthy adult volunteers under sixty-five years of age were enrolled during the 2018–2019 RSV season in Houston, TX. Blood was collected at three study visits. The kinetics of RSV-neutralizing, RSV F site-specific competitive, and RSV-binding antibodies in serum samples were measured by microneutralization and enzyme-linked immunosorbent assays. Three distinct profiles of RSV-specific antibody kinetics were identified that were consistent with RSV infection status: uninfected, acutely infected, and recently infected. The uninfected group had stable antibody titers for the duration of the study period (185 days). The acutely infected group had lower antibody responses at the beginning of the study, supporting a correlate of infection, followed by a significant antibody response after infection that was maintained for at least 125 days. Unlike the acutely infected group, the recently infected group had a significant precipitous decrease in RSV antibody in only 60 days. This study is the first, to our knowledge, to describe this abrupt loss of RSV-specific antibody in detail. This rapid decline of antibody may present an obstacle for the development of vaccines with lasting protection against RSV, and perhaps other respiratory pathogens. Neutralizing antibody responses were greater to prototypic than contemporaneous RSV strains, regardless of infection status, indicating that original antigenic sin may impact the humoral immune response to new or emerging RSV strains.

呼吸道合胞病毒 (RSV) 特异性血清抗体与保护感染和减少严重疾病相关，但再感染仍然很常见。在这项研究中，我们评估了自然 RSV 再感染后 RSV 特异性血清抗体活性，以检查成人体液免疫反应的寿命。2018-2019 年 RSV 季节期间，在德克萨斯州休斯敦招募了 19 名 65 岁以下的健康成年志愿者。在三次研究访视时采集血液。通过微量中和和酶联免疫吸附测定法测量血清样品中 RSV 中和抗体、RSV F 位点特异性竞争抗体和 RSV 结合抗体的动力学。确定了与 RSV 感染状态一致的三种不同的 RSV 特异性抗体动力学特征：未感染、急性感染、而且最近感染了。未感染组在研究期间（185 天）具有稳定的抗体滴度。急性感染组在研究开始时具有较低的抗体反应，支持感染的相关性，随后在感染后维持至少 125 天的显着抗体反应。与急性感染组不同，新近感染组的 RSV 抗体仅在 60 天内显着急剧下降。据我们所知，这项研究是第一个详细描述 RSV 特异性抗体突然丢失的研究。抗体的这种快速下降可能会阻碍疫苗的开发，从而对 RSV 和其他呼吸道病原体具有持久的保护作用。中和抗体对原型的反应比同时期的 RSV 毒株更大，