Kimotho John, Sein Yiakon, Sayed Shahin, Shah Reena, Mwai Kennedy, Saleh Mansoor, Wanjiku Perpetual, Mwacharo Jedidah, Nyagwange James, Karanja Henry, Kutima Bernadette, Gitonga John N, Mugo Daisy, Karanu Ann, Moranga Linda, Oluoch Viviane, Shah Jasmit, Mutiso Julius, Mburu Alfred, Nneka Zaitun, Betti Peter, Usyu Mutinda Wanzila, Issak Abdi Abdirahman, Bejon Philip, Isabella Ochola-Oyier Lynette, M Warimwe George, Nduati Eunice W, M Ndungu Francis
KEMRI-Wellcome Trust Research Programme, KILIFI, Coast, 230-80108, Kenya.
Pwani University, KILIFI, 230-80108, Kenya.
Wellcome Open Res. 2024 Dec 2;8:350. doi: 10.12688/wellcomeopenres.19414.2. eCollection 2023.
Given the low levels of coronavirus disease 2019 (COVID-19) vaccine coverage in sub-Saharan Africa (sSA), despite high levels of natural severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) exposures, strategies for extending the breadth and longevity of naturally acquired immunity are warranted. Designing such strategies will require a good understanding of naturally acquired immunity.
We measured whole-spike immunoglobulin G (IgG) and spike-receptor binding domain (RBD) total immunoglobulins (Igs) on 585 plasma samples collected longitudinally over five successive time points within six months of COVID-19 diagnosis in 309 COVID-19 patients. We measured antibody-neutralising potency against the wild-type (Wuhan) SARS-CoV-2 pseudovirus in a subset of 51 patients over three successive time points. Binding and neutralising antibody levels and potencies were then tested for correlations with COVID-19 severities.
Rates of seroconversion increased from day 0 (day of PCR testing) to day 180 (six months) (63.6% to 100 %) and (69.3 % to 97%) for anti-spike-IgG and anti-spike-RBD binding Igs, respectively. Levels of these binding antibodies peaked at day 28 (p<0.01) and were subsequently maintained for six months without significant decay (p>0.99). Similarly, antibody-neutralising potencies peaked at day 28 (p<0.01) but declined by three-fold, six months after COVID-19 diagnosis (p<0.01). Binding antibody levels were highly correlated with neutralising antibody potencies at all the time points analysed (r>0.60, p<0.01). Levels and potencies of binding and neutralising antibodies increased with disease severity.
Most COVID-19 patients generated SARS-CoV-2 specific binding antibodies that remained stable in the first six months of infection. However, the respective neutralising antibodies decayed three-fold by month-six of COVID-19 diagnosis suggesting that they are short-lived, consistent with what has been observed elsewhere in the world. Thus, regular vaccination boosters are required to sustain the high levels of anti-SARS-CoV-2 naturally acquired neutralising antibody potencies in our population.
鉴于撒哈拉以南非洲地区2019冠状病毒病（COVID-19）疫苗接种率较低，尽管该地区人群严重急性呼吸综合征冠状病毒2（SARS-CoV-2）自然暴露水平较高，但仍有必要制定策略以扩大自然获得性免疫的广度和持久性。制定此类策略需要充分了解自然获得性免疫。
我们对309例COVID-19患者在确诊后的六个月内连续五个时间点纵向采集的585份血浆样本，检测了全刺突免疫球蛋白G（IgG）和刺突受体结合域（RBD）总免疫球蛋白（Igs）。我们在51例患者的一个亚组中，连续三个时间点检测了针对野生型（武汉）SARS-CoV-2假病毒的抗体中和效力。然后测试结合抗体和中和抗体的水平及效力与COVID-19严重程度之间的相关性。
抗刺突-IgG和抗刺突-RBD结合Igs的血清转化率从第0天（PCR检测日）到第180天（六个月）分别从63.6%升至100%和从69.3%升至97%。这些结合抗体的水平在第28天达到峰值（p<0.01），随后在六个月内保持稳定，无显著下降（p>0.99）。同样，抗体中和效力在第28天达到峰值（p<0.01），但在COVID-19确诊六个月后下降了三倍（p<0.01）。在所有分析的时间点，结合抗体水平与中和抗体效力高度相关（r>0.60，p<0.01）。结合抗体和中和抗体的水平及效力随疾病严重程度增加。
大多数COVID-19患者产生了SARS-CoV-2特异性结合抗体，这些抗体在感染后的前六个月保持稳定。然而，中和抗体在COVID-19确诊后的第六个月下降了三倍，这表明它们的寿命较短，与世界其他地区的观察结果一致。因此，需要定期接种加强针，以维持我国人群中高水平的抗SARS-CoV-2自然获得性中和抗体效力。
