Stirrup Oliver, Tut Gokhan, Krutikov Maria, Bone David, Lancaster Tara, Azmi Borscha, Monakhov Igor, Moss Paul, Hayward Andrew, Copas Andrew, Shallcross Laura
Institute for Global Health, University College London, London, England, UK.
Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, England, UK.
Wellcome Open Res. 2024 Feb 19;9:45. doi: 10.12688/wellcomeopenres.20750.1. eCollection 2024.
We have previously demonstrated that older residents of long-term care facilities (LTCF) in the UK show levels of anti-spike antibodies that are comparable to the general population following primary series and booster vaccination for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, data on the humoral response to other SARS-CoV-2 proteins associated with natural infection are scarce in this vulnerable population.
We measured quantitative levels of anti-nucleocapsid antibodies in blood samples taken from LTCF residents and staff after initial and repeat SARS-CoV-2 infections, between December 2020 and March 2023. Data on SARS-CoV-2 infection and vaccination were obtained through linkage to national datasets. Linear mixed effects models were used to investigate anti-nucleocapsid antibody levels, using log10 scale, in relation to time from most recent infection. This included evaluation of associations between repeat infection, staff/resident status, age, sex, Omicron infection and vaccination history and peak antibody level and slope of decline with time.
We analysed 405 antibody observations from 220 residents and 396 observations from 215 staff. Repeat infection was associated with 8.5-fold (95%CI 4.9-14.8-fold) higher initial (peak) median anti-nucleocapsid antibody level, with steeper subsequent slope of decline. There were no significant differences in antibody level associated with resident (vs. staff) status or age, but Omicron infection was associated with 3.6-fold (95%CI 2.4-5.4-fold) higher levels. There was stronger evidence of waning of antibody levels over time in a sensitivity analysis in which observations were censored in cases with suspected undetected repeat infection.
We found similar levels of anti-nucleocapsid antibody in residents and staff of LTCFs. Repeat infection and infection with an Omicron strain were associated with higher peak values. There was evidence of waning of anti-nucleocapsid antibody levels over time.
我们之前已经证明，英国长期护理机构（LTCF）的老年居民在接种严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的初级系列疫苗和加强疫苗后，其抗刺突抗体水平与普通人群相当。然而，在这一脆弱人群中，关于对与自然感染相关的其他SARS-CoV-2蛋白的体液反应的数据却很少。
我们在2020年12月至2023年3月期间，对长期护理机构居民和工作人员在初次和再次感染SARS-CoV-2后采集的血液样本中的抗核衣壳抗体进行了定量检测。通过与国家数据集的关联获取了SARS-CoV-2感染和疫苗接种的数据。使用线性混合效应模型，以log10尺度研究抗核衣壳抗体水平与距最近一次感染的时间之间的关系。这包括评估重复感染、工作人员/居民身份、年龄、性别、奥密克戎感染和疫苗接种史与抗体峰值水平以及随时间下降斜率之间的关联。
我们分析了来自220名居民的405份抗体观察结果和来自215名工作人员的396份观察结果。重复感染与初始（峰值）抗核衣壳抗体中位数水平高8.5倍（95%CI为4.9 - 14.8倍）相关，随后下降斜率更陡。与居民（相对于工作人员）身份或年龄相关的抗体水平没有显著差异，但奥密克戎感染与抗体水平高3.6倍（95%CI为2.4 - 5.4倍）相关。在一项敏感性分析中，对于疑似未检测到的重复感染病例进行观察截尾时，有更强的证据表明抗体水平随时间下降。
我们发现长期护理机构居民和工作人员的抗核衣壳抗体水平相似。重复感染和奥密克戎毒株感染与更高的峰值相关。有证据表明抗核衣壳抗体水平随时间下降。
