Verheul Marije K, Nijhof Kim H, de Zeeuw-Brouwer Mary-Lène, Duijm Geraly, Ten Hulscher Hinke, de Rond Lia, Beckers Lisa, Eggink Dirk, van Tol Sophie, Reimerink Johan, Boer Mardi, van Beek Josine, Rots Nynke, van Binnendijk Rob, Buisman Anne-Marie
Centre for Immunology of Infectious Diseases and Vaccines, Center for Infectious Disease Control, National Institute for Public Health and the Environment, 3721 MA Bilthoven, The Netherlands.
Centre for Infectious Diseases Research, Diagnostics and Laboratory Surveillance, WHO COVID-19 Reference Laboratory, Center for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), 3721 MA Bilthoven, The Netherlands.
Vaccines (Basel). 2023 Jul 4;11(7):1196. doi: 10.3390/vaccines11071196.
The generation of a specific long-term immune response to SARS-CoV-2 is considered important for protection against COVID-19 infection and disease. Memory B cells, responsible for the generation of antibody-producing plasmablasts upon a new antigen encounter, play an important role in this process. Therefore, the induction of memory B cell responses after primary and booster SARS-CoV-2 immunizations was investigated in the general population with an emphasis on older adults. Participants, 20-99 years of age, due to receive the mRNA-1273 or BNT162b2 SARS-CoV-2 vaccine were included in the current study. Specific memory B cells were determined by ex vivo ELISpot assays. In a subset of participants, antibody levels, avidity, and virus neutralization capacity were compared to memory B cell responses. Memory B cells specific for both Spike S1 and receptor-binding domain (RBD) were detected in the majority of participants following the primary immunization series. However, a proportion of predominantly older adults showed low frequencies of specific memory B cells. Booster vaccination resulted in a large increase in the frequencies of S1- and RBD-specific memory B cells also for those in which low memory B cell frequencies were detected after the primary series. These data show that booster immunization is important for the generation of a memory B cell response, as a subset of older adults shows a suboptimal response to the primary SARS-CoV-2 immunization series. It is anticipated that these memory B cells will play a significant role in the immune response following viral re-exposure.
对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）产生特异性长期免疫反应被认为对预防冠状病毒病2019（COVID-19）感染和疾病很重要。记忆B细胞在这一过程中发挥重要作用，它负责在遇到新抗原时产生分泌抗体的浆母细胞。因此，本研究在普通人群中，重点针对老年人，调查了初次和加强接种SARS-CoV-2疫苗后记忆B细胞反应的诱导情况。本研究纳入了20至99岁、计划接种mRNA-1273或BNT162b2 SARS-CoV-2疫苗的参与者。通过体外酶联免疫斑点试验（ELISpot）测定特异性记忆B细胞。在一部分参与者中，将抗体水平、亲和力和病毒中和能力与记忆B细胞反应进行了比较。在大多数参与者完成初次免疫接种系列后，检测到了针对刺突蛋白S1和受体结合域（RBD）的特异性记忆B细胞。然而，一部分主要为老年人的参与者显示出特异性记忆B细胞频率较低。加强接种也使那些在初次接种系列后检测到记忆B细胞频率较低的参与者中，S1和RBD特异性记忆B细胞的频率大幅增加。这些数据表明，加强免疫对于记忆B细胞反应的产生很重要，因为一部分老年人对初次SARS-CoV-2免疫接种系列的反应欠佳。预计这些记忆B细胞将在病毒再次暴露后的免疫反应中发挥重要作用。
