National Laboratory Capacity Building Directorate, Ethiopian Public Health Institute, Addis Ababa, Ethiopia.
Department of Microbiology, Immunology and Parasitology, St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia.
Virol J. 2024 Aug 19;21(1):192. doi: 10.1186/s12985-024-02443-6.
Natural infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or vaccination triggers antibody production against key viral antigens. However, there is limited evidence on the levels of antibodies produced in naturally infected individuals compared to those vaccinated in Ethiopia. Therefore, we aimed to detect and compare SARS-CoV-2 antibodies produced by naturally infected and vaccinated individuals.
We conducted a multicenter cross-sectional study among a total of 355 naturally infected and 355 vaccinated individuals from November 2022 to April 2023 at 10 selected health facilities in Addis Ababa, Ethiopia. We enrolled the participants consecutively upon their arrival at health facilities until the required sample size was achieved. We used a structured questionnaire to collect data on the demographic and clinical characteristics of the participants. We also collected 3-5 ml of blood samples from all participants and tested for anti-Spike (anti-S) and anti-nucleocapsid (anti-N) antibodies using Cobas 6000. We utilized frequency, mean, or median to describe the data, the Mann-Whitney U test to compare groups, and a generalized linear regression model to assess factors associated with anti-S antibody concentration. We analyzed the data with SPSS version 26, and the level of significance was set at P-value < 0.05.
Of the naturally infected participants, 352 (99.5%) had anti-S antibodies and all (100%) had anti-N antibodies, whereas among vaccinated participants, all (100%) had anti-S antibodies, while 323 (91.6%) had anti-N antibodies. Anti-S antibodies produced by vaccinated individuals were significantly (P < 0.001) higher than those produced as a result of natural infection. Being young (P = 0.004), having hypertension (P < 0.001), and having diabetes (P < 0.001) were significantly associated with lower anti-S antibody levels, while being recently vaccinated and having a higher number of vaccine doses were significantly associated with higher anti-S antibody concentrations in vaccinated participants. Having diabetes (P < 0.001) were significantly associated with lower anti-S concentrations in participants who were naturally infected.
There is a high seropositivity rate in both naturally infected and vaccinated individuals. However, vaccinated individuals had higher levels of SARS-CoV-2 antibodies than those who were naturally infected, which highlights the significant contribution of vaccination in increasing the protection of COVID-19 in Ethiopia.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的自然感染或疫苗接种会引发针对关键病毒抗原的抗体产生。然而，与埃塞俄比亚接种疫苗的人群相比，自然感染人群产生的抗体水平的证据有限。因此，我们旨在检测和比较自然感染和接种疫苗人群产生的 SARS-CoV-2 抗体。
我们在 2022 年 11 月至 2023 年 4 月期间在埃塞俄比亚亚的斯亚贝巴的 10 个选定的卫生设施中对总共 355 名自然感染和 355 名接种疫苗的个体进行了多中心横断面研究。我们在参与者到达卫生设施时连续招募他们，直到达到所需的样本量。我们使用结构化问卷收集参与者的人口统计学和临床特征数据。我们还从所有参与者收集 3-5ml 的血液样本，并使用 Cobas 6000 检测针对刺突（anti-S）和核衣壳（anti-N）的抗体。我们使用频率、平均值或中位数来描述数据，使用曼-惠特尼 U 检验比较组，使用广义线性回归模型评估与抗 S 抗体浓度相关的因素。我们使用 SPSS 版本 26 分析数据，显著性水平设置为 P 值<0.05。
在自然感染的参与者中，352 名（99.5%）有抗 S 抗体，所有（100%）有抗 N 抗体，而在接种疫苗的参与者中，所有（100%）有抗 S 抗体，而 323 名（91.6%）有抗 N 抗体。接种疫苗个体产生的抗 S 抗体明显（P<0.001）高于自然感染产生的抗体。年轻（P=0.004）、高血压（P<0.001）和糖尿病（P<0.001）与较低的抗 S 抗体水平显著相关，而最近接种疫苗和接种疫苗剂量较高与接种疫苗参与者的抗 S 抗体浓度显著相关。自然感染的参与者中，糖尿病（P<0.001）与较低的抗 S 浓度显著相关。
自然感染和接种疫苗的个体均有较高的血清阳性率。然而，接种疫苗的个体产生的 SARS-CoV-2 抗体水平高于自然感染的个体，这突显了疫苗接种在增加埃塞俄比亚 COVID-19 保护方面的重要作用。
