A novel method for recombinant mammalian-expressed S-HBsAg virus-like particle production for assembly status analysis and improved anti-HBs serology.

The Hepatitis B surface antigen (HBsAg) as the only lipid-associated envelope protein of the Hepatitis B virus (HBV) acts as cellular attachment and entry mediator of HBV making it the main target of neutralizing antibodies to provide HBV immunity after infection or vaccination. Despite its central role in inducing protective immunity, there is however a surprising lack of comparative studies examining different HBsAgs and their ability to detect anti-HBs antibodies. On the contrary, various time-consuming complex HBsAg production protocols have been established, which result in structurally and functionally insufficiently characterized HBsAg.

The effects of single testosterone administration and stress induction on steroid hormone levels in hair.

Hair steroid analysis is increasingly recognized for its ability to capture cumulative hormone secretion, thought to reflect an individual's response to long-term environmental conditions. Despite its growing use, the influence of single, isolated events on hair steroid concentrations remains underexplored. Our study therefore examined the effects of a single-dose transdermal testosterone administration (150 mg) and acute laboratory stress induction on hair testosterone and cortisol levels in a randomized, between-subject, placebo-controlled, and double-blind design.

Antigenic cartography using variant-specific hamster sera reveals substantial antigenic variation among Omicron subvariants.

Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) has developed substantial antigenic variability. As the majority of the population now has pre-existing immunity due to infection or vaccination, the use of experimentally generated animal immune sera can be valuable for measuring antigenic differences between virus variants. Here, we immunized Syrian hamsters by two successive infections with one of nine SARS-CoV-2 variants.

Non-cross-reactive epitopes dominate the humoral immune response to COVID-19 vaccination - kinetics of plasma antibodies, plasmablasts and memory B cells.

Introduction: COVID-19 vaccines are highly effective in inducing protective immunity. While the serum antibody response to COVID-19 vaccination has been studied in depth, our knowledge of the underlying plasmablast and memory B cell (Bmem) responses is still incomplete. Here, we determined the antibody and B cell response to COVID-19 vaccination in a naïve population and contrasted it with the response to a single influenza vaccination in a primed cohort.

SARS-CoV-2 rapid antigen test sensitivity and viral load in newly symptomatic hospital employees in Berlin, Germany, December, 2020 to February, 2022: an observational study.

Background: Evolving SARS-CoV-2 variants and changing levels of pre-existing immunity require re-evaluation of antigen-detecting rapid diagnostic test (Ag-RDT) performance. We investigated possible associations between Ag-RDT sensitivity and various potential influencing factors, such as immunisation status and viral variant, in symptomatic hospital employees.

Methods: In this observational study, RT-PCR, Ag-RDT, and symptom-specific data were collected at three SARS-CoV-2 test centres for employees of the Charité-Universitätsmedizin Berlin hospital (Berlin, Germany).