Yamashita Keita, Suzuki Akira, Takebayashi Shiori, Toguchi Akihiro, Ogitani Kenya, Niizeki Noriyasu, Nagura Osanori, Furuhashi Kazuki, Iwaizumi Moriya, Maekawa Masato
Department of Laboratory Medicine, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
Vaccines (Basel). 2022 Jun 30;10(7):1050. doi: 10.3390/vaccines10071050.
Vaccines against SARS-CoV-2 with good efficacy are now available worldwide. However, gained immunity diminishes over time. Here, we investigate the course of both humoral and cell-mediated immunity in response to three doses of the Pfizer mRNA BNT162b2 SARS-CoV-2 vaccine in healthcare workers in Japan. SARS-CoV-2 anti-receptor-binding domain (RBD) antibodies (total Ig, IgG), neutralizing antibodies (NAb), and ELISpot were measured in serum and whole blood samples collected after each vaccine dose. ELISpot numbers were higher than the cutoff values in most participants at all times. It was suggested that the difference in behavior between humoral immunity and cell-mediated immunity with age is complementary. Anti-RBD total Ig, IgG, and NAb indicated a high correlation at each time point after vaccine doses. Total Ig was retained long-term after the second dose and increased significantly faster by the booster dose than IgG. Nab levels of all subjects were ≤20% six months after the second dose, and the correlation coefficient was greatly reduced. These are due to the avidity of each antibody and differences among commercial kits, which may affect the evaluation of immunokinetics in previous COVID-19 studies. Therefore, it is necessary to harmonize reagents categorized by the same characteristics.
目前，全球已有疗效良好的抗SARS-CoV-2疫苗。然而，获得的免疫力会随着时间的推移而减弱。在此，我们调查了日本医护人员接种三剂辉瑞mRNA BNT162b2 SARS-CoV-2疫苗后体液免疫和细胞介导免疫的过程。在每次接种疫苗后采集的血清和全血样本中检测SARS-CoV-2抗受体结合域（RBD）抗体（总Ig、IgG）、中和抗体（NAb）和ELISpot。在所有时间点，大多数参与者的ELISpot数值均高于临界值。研究表明，体液免疫和细胞介导免疫随年龄变化的行为差异具有互补性。接种疫苗后各时间点，抗RBD总Ig、IgG和NAb均显示出高度相关性。第二剂疫苗后，总Ig长期保持，且加强剂量使其增加速度明显快于IgG。第二剂疫苗接种六个月后，所有受试者的NAb水平均≤20%，且相关系数大幅降低。这些是由于每种抗体的亲和力以及商业试剂盒之间的差异所致，这可能会影响先前COVID-19研究中的免疫动力学评估。因此，有必要统一按相同特性分类的试剂。
