Since the onset of the COVID‐19 pandemic, humanity has experienced the spread and circulation of several SARS-CoV-2 variants that differed in transmissibility, contagiousness, and the ability to escape from vaccine-induced neutralizing antibodies. However, issues related to the differences of variant-specific immune responses, remain insufficiently studied. The aim of this study was to compare the parameters of the humoral immune responses in two groups of patients with acute COVID-19 who were infected during the circulation period of the D614G and the Delta variants of SARS-CoV-2. Sera from 48 patients with acute COVID-19 were tested for SARS-CoV-2 binding and neutralizing antibodies using six assays. We found that serum samples from the D614G period demonstrated 3.9‐ and 1.6‐fold increase in RBD- and Spike‐specific IgG binding with Wild type antigens compared with Delta variant antigens (p < 0.01). Cluster analysis showed the existence of two well-separated clusters. The first cluster mainly consisted of D614G period patients and the second cluster predominantly included patients from Delta period. The results thus obtained indicate that humoral immune responses in D614G- and Delta-specific infections can be characterized by variant-specific signatures. This can be taken into account when developing new variant-specific vaccines.

Atopic dermatitis (AD), a T2 inflammatory skin condition, is widely recognized as one of the most prevalent chronic and recurrent skin disorders. One of the most effective therapy for treating moderate-to-severe AD is Dupilumab, a monoclonal antibody that blocks both IL-4 and IL-13 signaling. At the same time, no comprehensive analysis of cytokines profile was made in AD patients undergoing Dupilumab therapy. The primary objective of our research was to examine the levels of main cytokines to better understanding systemic immune response in AD and to identify potential biomarkers of the effectiveness of Dupilumab treatment. AD patients demonstrated significant clinical improvements one year after initializing of Dupilumab therapy. We identified 16 cytokines that showed major difference between Dupilumab-treated patients and patients without Dupilumab therapy. Six cytokines showed correlation with AD severity and the efficacy of Dupilumab therapy. Jointly revealed cytokines could potentially predict the effectiveness of Dupilumab treatment and help to choose the precision target therapy in AD patients as well.