Year: 2025
Type: article
Study design: Observational Study
Abstract: Objectives To evaluate the immune persistence and cross-immune response of elderly individuals after Omicron BA.5 infections. Method The neutralizing antibodies against WT, BA.5, XBB.1 and EG.5 strains were analyzed. The T/B-cell subsets’ responses were tested through intracellular cytokine staining and flow cytometry. Results The neutralizing antibodies titers against WT and BA.5 strain, remaining high level for at least 6 months, were higher than that of both XBB.1 and EG.5 variants. The neutralizing antibodies of WT, BA.5, XBB.1, and EG.5 strains in the elderly were slightly lower than those in middle-age. The memory B cells decreased rapidly in the elderly, and Tfh, Th17 cells of the elderly continued to increase for only 3 months, while Tfh and Th17 cells increased in the middle-aged for over 6 months. For the elderly, after peptide stimulation, unswitched/switched memory B cells decreased, while double negative B cells displayed higher proliferation. The proportions of both naïve and Temra cells in CD4+ and CD8+ T cells declined, whereas those of Tcm and Tem cells elevated. In the meantime, both CD69+ and CD38+ T cells decreased, but the frequencies of PD-1+ and CTLA-4+ of CD4+ and CD8+ T cells showed an increasing trend. The proportions of PD-1+ and CTLA-4+ cells also increased in older people with long COVID symptoms at 3m post-infection. Conclusions Omicron BA.5 infection induced lower neutralizing antibodies against XBB.1 and EG.5 variant. The decrease of memory B cells, CD69+ and CD38+T cells, as well as the increase of PD-1+, CTLA-4+ of CD4+/CD8+T cells and double negative B cells, indicate that sustained immune responses against BA.5 infection may wane more rapidly in elderly populations.
Source: Frontiers in Immunology
Authors: Qin Luo, Qinqin Song, Yan Li, Kexin Zong, Ti Liu, Junming He, Guoyong Mei, Haijun Du, Zhiqiang Xia, Mi Liu, Juan Song, Chen Gao, Dong Xia, Guangyu Xue, Wenyan Tian, Yinli Qu, Zengqiang Kou, Zhongjun Dong, Jun Han
Institutions: Chinese Center For Disease Control and Prevention, National Institute for Viral Disease Control and Prevention, National Institute for Communicable Disease Control and Prevention, Shandong Center for Disease Control and Prevention, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an Jiaotong University, Beijing Tsinghua Chang Gung Hospital, Tsinghua University, Anhui Medical University, First Affiliated Hospital of Anhui Medical University, State Key Laboratory of Membrane Biology
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $3,801
OpenAlex ID: W4410247757