Dynamic changes of neutralizing antibody and memory T cell responses six months post Omicron XBB reinfection

• Published in: Frontiers in immunology Vol. 15; p. 1477721
• Main Authors: Zhao, Xin-Jing, Li, Xin-Lou, Zhang, Sheng, Chen, Jin-Jin, Zhao, Wei-Chao, Wu, Na-Na, Wang, Rui-Juan, Xu, Qiang, Lv, Chen-Long, Jiang, Bao-Gui, Wang, Guo-Lin, Fang, Li-Qun
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 07.10.2024
• Subjects: Adult; Antibodies, Neutralizing - immunology; Antibodies, Viral - blood; Antibodies, Viral - immunology; COVID-19 - immunology; COVID-19 Vaccines - immunology; Cross Reactions - immunology; cross-recognition; Female; Humans; immune persistence; Immunology; Male; memory T cell responses; Memory T Cells - immunology; Middle Aged; neutralizing antibody; Omicron XBB reinfection; Prospective Studies; Reinfection - immunology; SARS-CoV-2 - immunology; Spike Glycoprotein, Coronavirus - immunology; neutralizing antibody; memory T cell responses; Omicron XBB reinfection; cross-recognition; immune persistence
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2024.1477721

With the continued prevalence of COVID-19, repeated infection caused by SARS-CoV-2 has become common. However, studies on immune persistence post Omicron XBB reinfection are limited. We prospectively studied the durability and cross-reactivity of neutralizing antibodies (NAbs) and T cell responses among 20 subjects who suffered Omicron BA.5 infection with or without Omicron XBB reinfection over 6-month through the pseudovirus neutralization test and the fluorospot assay. NAbs against EG.5.1, BA.2.86, and JN.1 subvariants were decreased and undetectable at 6-month post Omicron BA.5 infection, while those elicited by Omicron XBB reinfection were significant increased and remained detectable against all detected variants within 6-month. Furthermore, in subjects with Omicron XBB reinfection, memory T cell responses could cross-recognized wild-type and Omicron spike peptides and reached peak at 3-month. Interestingly, comparable robust T cell responses were observed among non-seroconverted subjects post Omicron XBB exposure. Though the NAbs against various emerging Omicron subvariants elicited by Omicron XBB reinfection can persist for at least 6-month, the HCWs should strengthen personal protection and timely be immunized with updated vaccines upon current circulating variants or conserved T epitope.