Epidemiological and immunological characteristics of middle-aged and elderly people in housing estates after Omicron BA.5 wave in Jinan, China

• Published in: Heliyon Vol. 10; no. 19; p. e38382
• Main Authors: Zhao, Xin-Jing, Li, Min, Zhang, Sheng, Li, Ke, Wei, Wang-Qian, Chen, Jin-Jin, Xu, Qiang, Lv, Chen-Long, Liu, Ti, Wang, Guo-Lin, Fang, Li-Qun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.10.2024
• Subjects: antibodies; China; COVID-19 infection; elderly; Elderly population; Epidemiological characteristics; epidemiological studies; immunity; issues and policy; Neutralizing antibody; Omicron BA.5; people; Severe acute respiratory syndrome coronavirus 2; vaccination; Vaccination doses; China; Epidemiological characteristics; Vaccination doses; Omicron BA.5; Elderly population; Neutralizing antibody
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2024.e38382

A great number of COVID-19 patients was caused by Omicron BA.5 subvariant between December 2022 and January 2023 after the end of the zero-COVID-19 policy in China. In this study, we clarified the epidemiological and immunological characteristics of 457 enrolled middle-aged and elderly population in two housing estates after Omicron BA.5 wave. A total of 89.9 % (411/457) individuals have suffered Omicron BA.5 infection, among which 78.1 % (321/411) were symptomatic. The elderly patients were more likely to show fatigue and had longer symptomatic period than that of middle-aged patients post Omicron BA.5 infection. Omicron XBB and BA.2.86 subvariants extensively escaped the immunity elicited by Omicron BA.5 infection. The level of neutralizing antibody was mostly affected by vaccination doses rather than underlying disease status in these participants. It is very important to strengthen the epidemiological investigation and immune resistance assessment among elderly population for control of emerging SARS-CoV-2 variants. •Approximately 90 % participants were infected after Omicron BA.5 wave in Jinan.•The elderly subjects are more likely to show fatigue post Omicron BA.5 infection.•Omicron BA.5 infection elicits poor neutralizing antibodies against XBB and BA.2.86.•Vaccination doses is the key factor that associated with neutralizing activity.