tetano
Editor, Senior Moderator
Front Immunol
. 2025 May 9:16:1596065.
doi: 10.3389/fimmu.2025.1596065. eCollection 2025. Reduced immune response to SARS-CoV-2 infection in the elderly after 6 months
Qin Luo[SUP] #[/SUP][SUP] 1 [/SUP], Qinqin Song[SUP] #[/SUP][SUP] 1 [/SUP], Yan Li[SUP] #[/SUP][SUP] 2 [/SUP], Kexin Zong[SUP] 3 [/SUP], Ti Liu[SUP] 2 [/SUP], Junming He[SUP] 4 [/SUP], Guoyong Mei[SUP] 1 [/SUP], Haijun Du[SUP] 1 [/SUP], Zhiqiang Xia[SUP] 1 [/SUP], Mi Liu[SUP] 1 [/SUP], Juan Song[SUP] 1 [/SUP], Chen Gao[SUP] 1 [/SUP], Dong Xia[SUP] 1 [/SUP], Guangyu Xue[SUP] 1 [/SUP], Wenyan Tian[SUP] 1 [/SUP], Yinli Qu[SUP] 1 [/SUP], Zengqiang Kou[SUP] 2 [/SUP], Zhongjun Dong[SUP] 5 6 [/SUP], Jun Han[SUP] 1 [/SUP]
Affiliations
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[SUP]+[/SUP] and CD8[SUP]+[/SUP] T cells declined, whereas those of Tcm and Tem cells elevated. In the meantime, both CD69[SUP]+[/SUP] and CD38[SUP]+[/SUP] T cells decreased, but the frequencies of PD-1[SUP]+[/SUP] and CTLA-4[SUP]+[/SUP] of CD4[SUP]+[/SUP] and CD8[SUP]+[/SUP] T cells showed an increasing trend. The proportions of PD-1[SUP]+[/SUP] and CTLA-4[SUP]+[/SUP] 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[SUP]+[/SUP] and CD38[SUP]+[/SUP]T cells, as well as the increase of PD-1[SUP]+[/SUP], CTLA-4[SUP]+[/SUP] of CD4[SUP]+[/SUP]/CD8[SUP]+[/SUP]T cells and double negative B cells, indicate that sustained immune responses against BA.5 infection may wane more rapidly in elderly populations.
Keywords: T cell; adaptive immunity; elderly; neutralizing antibody; omicron BA.5.
. 2025 May 9:16:1596065.
doi: 10.3389/fimmu.2025.1596065. eCollection 2025. Reduced immune response to SARS-CoV-2 infection in the elderly after 6 months
Qin Luo[SUP] #[/SUP][SUP] 1 [/SUP], Qinqin Song[SUP] #[/SUP][SUP] 1 [/SUP], Yan Li[SUP] #[/SUP][SUP] 2 [/SUP], Kexin Zong[SUP] 3 [/SUP], Ti Liu[SUP] 2 [/SUP], Junming He[SUP] 4 [/SUP], Guoyong Mei[SUP] 1 [/SUP], Haijun Du[SUP] 1 [/SUP], Zhiqiang Xia[SUP] 1 [/SUP], Mi Liu[SUP] 1 [/SUP], Juan Song[SUP] 1 [/SUP], Chen Gao[SUP] 1 [/SUP], Dong Xia[SUP] 1 [/SUP], Guangyu Xue[SUP] 1 [/SUP], Wenyan Tian[SUP] 1 [/SUP], Yinli Qu[SUP] 1 [/SUP], Zengqiang Kou[SUP] 2 [/SUP], Zhongjun Dong[SUP] 5 6 [/SUP], Jun Han[SUP] 1 [/SUP]
Affiliations
- PMID: 40416973
- PMCID: PMC12098630
- DOI: 10.3389/fimmu.2025.1596065
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[SUP]+[/SUP] and CD8[SUP]+[/SUP] T cells declined, whereas those of Tcm and Tem cells elevated. In the meantime, both CD69[SUP]+[/SUP] and CD38[SUP]+[/SUP] T cells decreased, but the frequencies of PD-1[SUP]+[/SUP] and CTLA-4[SUP]+[/SUP] of CD4[SUP]+[/SUP] and CD8[SUP]+[/SUP] T cells showed an increasing trend. The proportions of PD-1[SUP]+[/SUP] and CTLA-4[SUP]+[/SUP] 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[SUP]+[/SUP] and CD38[SUP]+[/SUP]T cells, as well as the increase of PD-1[SUP]+[/SUP], CTLA-4[SUP]+[/SUP] of CD4[SUP]+[/SUP]/CD8[SUP]+[/SUP]T cells and double negative B cells, indicate that sustained immune responses against BA.5 infection may wane more rapidly in elderly populations.
Keywords: T cell; adaptive immunity; elderly; neutralizing antibody; omicron BA.5.