Analysis of related factors of plasma antibody levels in patients with severe and critical COVID-19

Abstract

Abstract Coronavirus disease 2019 (COVID-19) continues to impact global public health. The sever acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become less virulent as it mutates, so China relaxed its control the at the end of 2022. With the full opening, many COVID-19 patients have begun to appear. Therefore, we conducted a study to explore the correlation between plasma antibody level and baseline conditions or clinical outcomes in severe and critical patients. We collected the basic information of 79 included patients. ELISA tests were performed on plasma samples. The receptor-binding domain (RBD) IgG antibody level of mild group was significantly higher than that of severe/critical group (P = 0.00049). And in severe/critical group, there existed association between plasma antibody levels and age (P < 0.001, r = - 0.471), as well as plasma antibody levels and vaccination status (P = 0.00147, eta2 = 0.211). Between the mild and severe/critical patients, the level of RBD (Omicron BA.4/5) IgG antibody was significantly different. Besides, the level of plasma antibody seemed to be correlated with the age, suggesting that infection in the elderly should be paid more attention. And plasma antibody levels were strongly associated with vaccination status in the severe/critical patients.