Serology survey against multiple SARS-CoV-2 variants of residents in Tainan, Taiwan

Background: The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its evolving variants, continues to challenge global efforts to control its spread. Ongoing mutations may enhance transmissibility or lead to breakthrough infections, making immune monitoring crucial for public health policies. Methods: A SARS-CoV-2 variant protein microarray was used to assess total and neutralizing antibodies against multiple variants. A serological survey was conducted in October 2022 in Tainan, Taiwan, including general citizens and special medical care groups. The general population comprised residents from the city (n = 504), suburban (n = 166), and country areas (n = 88). Special groups included individuals in elderly care centers (n = 50), nursing homes (n = 51), kidney dialysis patients (n = 100), and people living with human immunodeficiency virus (PLWH) (n = 45). Statistical analyses were performed using one-way and repeated-measures analysis of variance (ANOVA). Results: The results demonstrated that the neutralization efficacy against Omicron and its subtypes declined according to the evolution of the variants, particularly in city and suburban areas. Special medical care populations, including individuals in elderly care centers, nursing homes, those undergoing kidney dialysis, and those PLWH, exhibited lower neutralization effectiveness. After analyzing the infection status, it can be found that special medical care populations had higher infection rates, especially in elderly care centers and nursing homes. Conclusions: SARS-CoV-2 protein microarray analysis is essential for assessing immunity at a population level. The findings highlight the need for adjusted vaccination strategies and ongoing surveillance of humoral immunity to address emerging SARS-CoV-2 variants effectively.