Bullock Jimmie L, Hickey Thomas E, Kemp Troy J, Metz Jordan, Loftus Sarah, Haynesworth Katarzyna, Castro Nicholas, Luke Brian T, Lowy Douglas R, Pinto Ligia A
Vaccine, Immunity and Cancer Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
Bioinformatics and Computational Science Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21702, USA.
Vaccines (Basel). 2024 May 9;12(5):516. doi: 10.3390/vaccines12050516.
SARS-CoV-2 vaccination-induced protection against infection is likely to be affected by functional antibody features. To understand the kinetics of antibody responses in healthy individuals after primary series and third vaccine doses, sera from the recipients of the two licensed SARS-CoV-2 mRNA vaccines were assessed for circulating anti-SARS-CoV-2 spike IgG levels and avidity for up to 6 months post-primary series and 9 months after the third dose. Following primary series vaccination, anti-SARS-CoV-2 spike IgG levels declined from months 1 to 6, while avidity increased through month 6, irrespective of the vaccine received. The third dose of either vaccine increased anti-SARS-CoV-2 spike IgG levels and avidity and appeared to enhance antibody level persistence-generating a slower rate of decline in the 3 months following the third dose compared to the decline seen after the primary series alone. The third dose of both vaccines induced significant avidity increases 1 month after vaccination compared to the avidity response 6 months post-primary series vaccination ( ≤ 0.001). A significant difference in avidity responses between the two vaccines was observed 6 months post-third dose, where the BNT162b2 recipients had higher antibody avidity levels compared to the mRNA-1273 recipients ( = 0.020).
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）疫苗接种所诱导的抗感染保护作用可能会受到功能性抗体特征的影响。为了解健康个体在完成初始疫苗接种系列和接种第三剂疫苗后的抗体反应动力学，对两种已获许可的SARS-CoV-2信使核糖核酸（mRNA）疫苗接种者的血清进行了评估，以检测其循环抗SARS-CoV-2刺突蛋白免疫球蛋白G（IgG）水平及亲和力，最长检测至初始疫苗接种系列后的6个月以及第三剂疫苗接种后的9个月。在完成初始疫苗接种系列后，抗SARS-CoV-2刺突蛋白IgG水平在第1至6个月下降，而亲和力在第6个月前不断上升，与所接种的疫苗无关。两种疫苗的第三剂均提高了抗SARS-CoV-2刺突蛋白IgG水平及亲和力，且似乎增强了抗体水平的持久性——与仅完成初始疫苗接种系列后的下降情况相比，第三剂疫苗接种后3个月内抗体水平下降速度较慢。与初始疫苗接种系列后6个月的亲和力反应相比，两种疫苗的第三剂在接种后1个月均诱导了显著的亲和力增加（P≤0.001）。在接种第三剂疫苗6个月后，观察到两种疫苗的亲和力反应存在显著差异，其中接种BNT162b2疫苗的受种者抗体亲和力水平高于接种mRNA-1273疫苗的受种者（P=0.020）。
