Kato Hideaki, Sano Kaori, Miyakawa Kei, Kurosawa Takayuki, Horikawa Kazuo, Kimura Yayoi, Goto Atsushi, Ryo Akihide
Infection Prevention and Control Department, Yokohama City University Hospital, Yokohama 236-0004, Japan.
Emerging Infectious Diseases Research Center, Yokohama City University Hospital, Yokohama 236-0004, Japan.
Infect Dis Rep. 2025 Apr 29;17(3):42. doi: 10.3390/idr17030042.
The long-term effects of multiple updated vaccinations against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) have not been clarified. Humoral or cellular immunity dynamics in healthcare workers for four years were analyzed. Blood samples were collected at five time points from April 2021 to January 2024. Humoral immunity was analyzed using the 50% neutralizing titer (NT) against the original Omicron XBB and Omicron BA.2.86 strains and cellular immunity were analyzed using the ELISpot interferon-gamma releasing assay. NTs and the spot-forming count (SFC) of the ELISpot assay were compared in the SARS-CoV-2 Omicron XBB-, Omicron-infected, and uninfected subjects. : 32 healthcare workers (median age, 47 years) who received 3-7 vaccine doses were enrolled. The NTs against the original strain decreased after the second vaccination but were maintained after the third vaccine dose. NTs against the Omicron XBB and BA.2.86 strains were detected before the Omicron vaccine was introduced and increased following the updated vaccination. The NTs against the Omicron XBB and BA.2.86 strains were elevated after natural infection by the Omicron strain, albeit without differences compared with the findings in uninfected subjects. Multivariate regression analysis revealed no confounder that affected the antibody titer against the BA.2.86 strain at the fifth blood sampling. The median number of SFCs ranged from 78 to 208 after the first two doses. : Multiple vaccinations induced the production of antibodies with divergent activity against emerging mutant strains and enhanced protective effects against the original strain. This finding supported the importance of updated vaccination.
针对严重急性呼吸综合征冠状病毒2（SARS-CoV-2）多次更新疫苗接种的长期影响尚未明确。分析了医护人员四年中的体液或细胞免疫动态。在2021年4月至2024年1月的五个时间点采集血样。使用针对原始奥密克戎XBB和奥密克戎BA.2.86毒株的50%中和滴度（NT）分析体液免疫，并使用酶联免疫斑点法（ELISpot）检测干扰素-γ释放分析细胞免疫。比较了SARS-CoV-2奥密克戎XBB、奥密克戎感染和未感染受试者的NT和ELISpot分析的斑点形成计数（SFC）。纳入了32名接受3 - 7剂疫苗接种的医护人员（中位年龄47岁）。针对原始毒株的NT在第二次接种后下降，但在第三次接种后维持。在引入奥密克戎疫苗之前就检测到了针对奥密克戎XBB和BA.2.86毒株的NT，在更新接种后增加。奥密克戎毒株自然感染后针对奥密克戎XBB和BA.2.86毒株的NT升高，尽管与未感染受试者的结果无差异。多变量回归分析显示，在第五次采血时，没有混杂因素影响针对BA.2.86毒株的抗体滴度。在前两剂接种后，SFC的中位数范围为78至208。多次接种诱导产生了对新出现的突变株具有不同活性的抗体，并增强了对原始毒株的保护作用。这一发现支持了更新接种的重要性。
