Fig. 4.

Medical conditions correlating with the induction of antibodies targeting SARS-CoV-2 structural proteins in patients after confirmed infection with SARS-CoV-2. All samples were tested by ELISA on SARS-CoV-2 protein-covered plates, and normalized using reference serum (as described by Miura et al. [24, 25]). Normalized ELISA units are presented: vertical lines in the boxes, median; boxes, values within second and third quartile; whiskers, sd; dots at the side of each box, real distribution of individual reads. Statistical analysis by non-parametric ANOVA and Kruskal–Wallis test (a) or by Mann–Whitney U test (b, c, d). (a) Severity of COVID-19 correlated to increased protein-specific antibody production. Patients were assigned to the groups by the physicians, with regard to symptoms, required treatment procedures, and length of the disease. (b) Rise of body temperature during infection over 38 °C was a predictor of SARS-CoV-2 structural protein-specific antibody induction. Samples from patients after infection were grouped according to observed (positive) or not observed (negative) body temperature over 38 °C. (c) Breathing difficulties during infection was an inadequate predictor of SARS-CoV-2 structural protein-specific antibody induction. Samples from patients after infection were grouped according to observed (positive) or not observed (negative) breathing difficulties. (d) Cough during infection as a positive predictor of SARS-CoV-2 structural protein-specific antibody induction. Samples from patients after infection were grouped according to observed (positive) or not observed (negative) cough in patients.