Association Between NK Cell Genetic Variants and the Development of Long COVID Associated- and Prepandemic Small Fiber Neuropathy.

Long coronavirus disease 2019 (COVID) (LC) symptoms including pain and autonomic dysfunction are in some patients associated with small-fiber neuropathy (SFN). The pathomechanisms underlying SFN are mostly unclear. Natural killer (NK) cells play a crucial role in immune regulation, viral clearance and nerve metabolism.

Association between human genetic variants affecting the host NK cell response and the development of herpes simplex virus type 1 encephalitis.

Herpes simplex virus encephalitis (HSE) is a rare complication of herpes simplex virus type 1 (HSV-1) infection or reactivation. It is so far unclear why only few patients develop HSE. As natural killer (NK) cells provide an important defense against HSV-1, we investigated whether there is an association between distinct human genetic variants associated with the host NK cell response and HSE.

Prediction of humoral and cellular immune response to COVID-19 mRNA vaccination by TTV load in kidney transplant recipients and hemodialysis patients.

Background: Immunosuppressed individuals such as kidney transplant recipients (KTR) and hemodialysis patients (DP) show impaired immune responses to COVID-19 vaccination. Plasma Torque Teno Virus (TTV) DNA load is used as surrogate for the individual degree of immunosuppression. We now assessed the association of TTV load at time of COVID-19 vaccination with humoral and cellular immune response rates to vaccination in KTR, DP, and healthy medical personnel (MP).

Comprehensive Comparison of Seven SARS-CoV-2-Specific Surrogate Virus Neutralization and Anti-Spike IgG Antibody Assays Using a Live-Virus Neutralization Assay as a Reference.

Neutralizing antibodies (nAbs) are considered a valuable marker for measuring humoral immunity against SARS-CoV-2. However, live-virus neutralization tests (NTs) require high-biosafety-level laboratories and are time-consuming. Therefore, surrogate virus neutralization tests (sVNTs) have been widely applied, but unlike most anti-spike (S) antibody assays, NTs and sVNTs are not harmonized, requiring further evaluation and comparative analyses.

Reduced Sensitivity of Commercial Spike-Specific Antibody Assays after Primary Infection with the SARS-CoV-2 Omicron Variant.

The SARS-CoV-2 Omicron variant is characterized by substantial changes in the antigenic structure of the Spike (S) protein. Therefore, antibodies induced by primary Omicron infection lack neutralizing activity against earlier variants. In this study, we analyzed whether these antigenic changes impact the sensitivity of commercial anti-SARS-CoV-2 antibody assays.

Different Neutralization Profiles After Primary SARS-CoV-2 Omicron BA.1 and BA.2 Infections.

Background And Methods: The SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) Omicron (B.1.1.

The First Case of Usutu Virus Neuroinvasive Disease in Austria, 2021.

Usutu virus (USUV) is a mosquito-borne flavivirus closely related to West Nile virus (WNV) that is endemic in many European countries. We report the first case of USUV neuroinvasive disease in Austria and discuss challenges in differentiating USUV from WNV infections in areas where both viruses are endemic.

Heterogeneous SARS-CoV-2-Neutralizing Activities After Infection and Vaccination.

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) with different resistance levels to existing immunity have recently emerged. Antibodies that recognize the SARS-CoV-2 spike (S) protein and exhibit neutralizing activities are considered the best correlate of protection and an understanding of humoral immunity is crucial for controlling the pandemic. We thus analyzed such antibodies in individuals recovered from infection in 2020 as well as vaccinees after two doses of an mRNA vaccine.

B Cell Depletion and SARS-CoV-2 Vaccine Responses in Neuroimmunologic Patients.

Objective: The study was undertaken to assess the impact of B cell depletion on humoral and cellular immune responses to severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) vaccination in patients with various neuroimmunologic disorders on anti-CD20 therapy. This included an analysis of the T cell vaccine response to the SARS-CoV-2 Delta variant.

Methods: We investigated prospectively humoral and cellular responses to SARS-CoV-2 mRNA vaccination in 82 patients with neuroimmunologic disorders on anti-CD20 therapy and 82 age- and sex-matched healthy controls.

SARS-CoV-2 vaccination in rituximab-treated patients: B cells promote humoral immune responses in the presence of T-cell-mediated immunity.

Objectives: Evidence suggests that B cell-depleting therapy with rituximab (RTX) affects humoral immune response after vaccination. It remains unclear whether RTX-treated patients can develop a humoral and T-cell-mediated immune response against SARS-CoV-2 after immunisation.

Methods: Patients under RTX treatment (n=74) were vaccinated twice with either mRNA-1273 or BNT162b2.

SARS-CoV-2 mutations in MHC-I-restricted epitopes evade CD8 T cell responses.

CD8 T cell immunity to SARS-CoV-2 has been implicated in COVID-19 severity and virus control. Here, we identified nonsynonymous mutations in MHC-I-restricted CD8 T cell epitopes after deep sequencing of 747 SARS-CoV-2 virus isolates. Mutant peptides exhibited diminished or abrogated MHC-I binding in a cell-free in vitro assay.

Assessment of S1-, S2-, and NCP-Specific IgM, IgA, and IgG Antibody Kinetics in Acute SARS-CoV-2 Infection by a Microarray and Twelve Other Immunoassays.

In this study, we comprehensively analyzed multispecific antibody kinetics of different immunoglobulins in hospitalized patients with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Three hundred fifty-four blood samples longitudinally obtained from 81 IgG-seroconverting progressed coronavirus disease 2019 (CoVID-19) patients were quantified for spike 1 (S1), S2, and nucleocapsid protein (NCP)-specific IgM, IgA, IgG, and total Ig antibodies using a microarray, 11 different enzyme-linked immunosorbent assays (ELISAs)/chemiluminescence immunoassays (CLIAs), and 1 rapid test by seven manufacturers. The assays' specificity was assessed in 130 non-CoVID-19 pneumonia patients.