Heterogenous CD8+ T Cell Maturation and 'Polarization' in Acute and Convalescent COVID-19 Patients.

Background: The adaptive antiviral immune response requires interaction between CD8+ T cells, dendritic cells, and Th1 cells for controlling SARS-CoV-2 infection, but the data regarding the role of CD8+ T cells in the acute phase of COVID-19 and post-COVID-19 syndrome are still limited.

Methods: . Peripheral blood samples collected from patients with acute COVID-19 ( 71), convalescent subjects bearing serum SARS-CoV-2 N-protein-specific IgG antibodies ( 51), and healthy volunteers with no detectable antibodies to any SARS-CoV-2 proteins (HC, 46) were analyzed using 10-color flow cytometry.

SARS-CoV-2 herd immunity of the Kyrgyz population in 2021.

In the fight against coronavirus infection, control of the immune response is of decisive importance, an important component of which is the seroprevalence of antibodies to SARS-CoV-2. Immunity to SARS-CoV-2 is formed either naturally or artificially through vaccination. The purpose of this study was to assess the seroprevalence of antibodies to SARS-CoV-2 in the population of Kyrgyzstan.

Alterations in B Cell and Follicular T-Helper Cell Subsets in Patients with Acute COVID-19 and COVID-19 Convalescents.

Background: Humoral immunity requires interaction between B cell and T follicular helper cells (Tfh) to produce effective immune response, but the data regarding a role of B cells and Tfh in SARS-CoV-2 defense are still sparse.

Methods: Blood samples from patients with acute COVID-19 ( = 64), convalescents patients who had specific IgG to SARS-CoV-2 N-protein ( = 55), and healthy donors with no detectable antibodies to any SARS-CoV-2 proteins (HC, = 44) were analyses by multicolor flow cytometry.

Results: Patients with acute COVID-19 showed decreased levels of memory B cells subsets and increased proportion plasma cell precursors compared to HC and COVID-19 convalescent patients, whereas for the latter the elevated numbers of virgin naïve, Bm2' and "Bm3+Bm4" was found if compared with HC.

Changes in Anti-SARS-CoV-2 IgG Subclasses over Time and in Association with Disease Severity.

IgG is the most prominent marker of post-COVID-19 immunity. Not only does this subtype mark the late stages of infection, but it also stays in the body for a timespan of at least 6 months. However, different IgG subclasses have different properties, and their roles in specific anti-COVID-19 responses have yet to be determined.

Longitudinal Randomized Cohort Study of SARS-CoV-2 Antibody Seroprevalence in the St. Petersburg Population.

Introduction. Since the detection of the first COVID-19 patient, 2 years have passed, during which more than 287,862,000 people have fallen ill globally, of which about 1.9% died.

Algorithm for laboratory diagnostics of parvoviral infection in risk groups.

Parvovirus infection (PVI) is widespread, characterized by airborne, bloodborne and vertical transmission routes. Parvovirus B19 (PVB19) exhibits tropism to erythropoietic cells. According to the increased likelihood principle of PVB19 infection and the severity of the consequences, immunocompromised individuals, especially those with hematological manifestations of diseases, are in increased risk group.

[Results of a study of parvovirus B19 (Parvoviridae, Parvovirinae, Erythroparvovirus, Primate erythroparvovirus 1) prevalence and circulation activity in socially significant categories of the population].

Unlabelled: Currently, along with the increasing need of medical organizations for blood preparations, algorithms for laboratory testing of blood donors are not available for all infections with hemo-contact mechanism of transmission. A representative example is infection caused by parvovirus В19.

Purpose Of The Study: The article presents the results of the original study, the purpose of which was to study the prevalence of antibodies to parvovirus B19 and the activity of the circulation of this virus in socially important categories of the population.