Macdonald Patrick J, Schaub Jeffrey M, Ruan Qiaoqiao, Williams Carroll L, Prostko John C, Tetin Sergey Y
Applied Research and Technology, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, IL USA.
Commun Med (Lond). 2022 Aug 25;2:109. doi: 10.1038/s43856-022-00174-9. eCollection 2022.
Measuring anti-viral antibody affinity in blood plasma or serum is a rational quantitative approach to assess humoral immune response and acquired protection. Three common vaccines against SARS-CoV-2-Comirnaty developed by Pfizer/BioNTech, Spikevax developed by Moderna/NIAID, and Jcovden (previously Janssen COVID-19 Vaccine) developed by Johnson & Johnson/Janssen (J&J)-induce antibodies to a variety of immunogenic epitopes including the epitopes located in the ACE2 receptor-binding domain (RBD) of the spike protein. Blocking RBD with antibodies interferes with the binding of the virus to ACE2 thus protecting against infection.
We perform measurements in the serum of the recipients of Pfizer, Moderna, and J&J vaccines, and we compare the apparent affinities of vaccine-induced antibodies against the RBD of the ancestral SARS-CoV-2 virus and the Delta and Omicron variants. We use our recently published method to determine the apparent affinity of anti-spike protein antibodies directly in human serum. This involves probing antibody-antigen equilibria with a small number of antigen-coated magnetic microparticles and imaging them on a fluorescence microscope.
Recipients of two-dose Pfizer and Moderna vaccines, as well as recipients of the single-dose J&J vaccine, develop high-affinity antibodies toward RBD derived from ancestral SARS-CoV-2. Affinities of these antibodies to Delta-RBD are approximately 10 times weaker, and even more drastically reduced (∼1000-fold) toward Omicron-RBD.
Vaccine-induced antibodies against ancestral SARS-CoV-2 RBD demonstrate ~10-fold and ~1000-fold weaker affinities toward Delta- and Omicron-RBD, respectively. Our approach offers a direct means for evaluating vaccine-induced adaptive immunity and can be helpful in designing or updating vaccines.
测量血浆或血清中的抗病毒抗体亲和力是评估体液免疫反应和获得性保护的合理定量方法。三种常见的针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的疫苗——辉瑞/生物新技术公司研发的Comirnaty、莫德纳/美国国立过敏与传染病研究所（NIAID）研发的Spikevax以及强生/杨森公司（J&J）研发的Jcovden（原名强生新冠疫苗）——可诱导针对多种免疫原性表位的抗体，包括位于刺突蛋白的血管紧张素转换酶2（ACE2）受体结合域（RBD）中的表位。抗体阻断RBD会干扰病毒与ACE2的结合，从而预防感染。
我们对辉瑞、莫德纳和强生疫苗接种者的血清进行测量，并比较疫苗诱导的抗体针对原始SARS-CoV-2病毒以及Delta和Omicron变体的RBD的表观亲和力。我们使用我们最近发表的方法直接在人血清中测定抗刺突蛋白抗体的表观亲和力。这涉及用少量包被抗原的磁性微粒探测抗体-抗原平衡，并在荧光显微镜下对其成像。
两剂辉瑞和莫德纳疫苗的接种者以及单剂强生疫苗的接种者均产生了针对源自原始SARS-CoV-2的RBD的高亲和力抗体。这些抗体与Delta-RBD的亲和力约弱10倍，而与Omicron-RBD的亲和力则大幅降低（约1000倍）。
疫苗诱导的针对原始SARS-CoV-2 RBD的抗体对Delta-RBD和Omicron-RBD的亲和力分别弱约10倍和约1000倍。我们的方法为评估疫苗诱导的适应性免疫提供了一种直接手段，有助于疫苗的设计或更新。
