Risk of Severe Acute Respiratory Syndrome Coronavirus 2 Infection Following Prior Infection or Vaccination.

Background: The extent to which infection versus vaccination has conferred similarly durable severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity during the Omicron era remains unclear.

Methods: In a cohort of 4496 adults under continued serological surveillance throughout the first year of Omicron-predominant SARS-CoV-2 transmission, we examined incidence of new infection among individuals whose last known antigenic exposure was either recent (<90 days) or remote (≥90 days) infection or vaccination.

Results: We adjudicated 2053 new-onset infections occurring between 15 December 2021 through 22 December 2022.

Serological response to vaccination in post-acute sequelae of COVID.

Background: Individuals with post-acute sequelae of COVID (PASC) may have a persistence in immune activation that differentiates them from individuals who have recovered from COVID without clinical sequelae. To investigate how humoral immune activation may vary in this regard, we compared patterns of vaccine-provoked serological response in patients with PASC compared to individuals recovered from prior COVID without PASC.

Methods: We prospectively studied 245 adults clinically diagnosed with PASC and 86 adults successfully recovered from prior COVID.

Awareness of SARS-CoV-2 Omicron Variant Infection Among Adults With Recent COVID-19 Seropositivity.

Importance: Some individuals who were infected by the SARS-CoV-2 Omicron variant may have been completely unaware of their infectious status while the virus was actively transmissible.

Objective: To examine awareness of infectious status among individuals during the recent Omicron variant surge in a diverse and populous urban region of Los Angeles County.

Design, Setting, And Participants: This cohort study analyzed the records of adult employees and patients of an academic medical center who were enrolled in a longitudinal COVID-19 serological study in Los Angeles County, California.

Demographic and clinical characteristics associated with variations in antibody response to BNT162b2 COVID-19 vaccination among healthcare workers at an academic medical centre: a longitudinal cohort analysis.

Objectives: We sought to understand the demographic and clinical factors associated with variations in longitudinal antibody response following completion of two-dose regiment of BNT162b2 vaccination.

Design: This study is a 10-month longitudinal cohort study of healthcare workers and serially measured anti-spike protein IgG (IgG-S) antibody levels using mixed linear models to examine their associations with participant characteristics.

Setting: A large, multisite academic medical centre in Southern California, USA.

A Comparison of Component Positioning Between Fluoroscopy-Assisted and Robotic-Assisted Total Hip Arthroplasty.

Background: This single-surgeon retrospective study examined a consecutive series of direct anterior approach total hip arthroplasties (THAs). Differences for the accuracy of acetabular component placement, leg length discrepancy, femoral offset, and absolute global offset difference were measured for patients who underwent hip replacement surgery with either fluoroscopic or robotic guidance.

Methods: One hundred THAs were included in both the fluoroscopically guided and robotically guided groups in the study.

The T-cell clonal response to SARS-CoV-2 vaccination in inflammatory bowel disease patients is augmented by anti-TNF therapy and often deficient in antibody-responders.

Background: Vaccination against SARS-CoV-2 is a highly effective strategy to protect against infection, which is predominantly mediated by vaccine-induced antibodies. Postvaccination antibodies are robustly produced by those with inflammatory bowel disease (IBD) even on immune-modifying therapies but are blunted by anti-TNF therapy. In contrast, T-cell response which primarily determines long-term efficacy against disease progression,, is less well understood.

Longitudinal SARS-CoV-2 mRNA Vaccine-Induced Humoral Immune Responses in Patients with Cancer.

Longitudinal studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine-induced immune responses in patients with cancer are needed to optimize clinical care. In a prospective cohort study of 366 (291 vaccinated) patients, we measured antibody levels [anti-spike (IgG-(S-RBD) and anti-nucleocapsid immunoglobulin] at three time points. Antibody level trajectories and frequency of breakthrough infections were evaluated by tumor type and timing of treatment relative to vaccination.

Antibody responses to the BNT162b2 mRNA vaccine in individuals previously infected with SARS-CoV-2.

In a cohort of BNT162b2 (Pfizer-BioNTech) mRNA vaccine recipients (n = 1,090), we observed that spike-specific IgG antibody levels and ACE2 antibody binding inhibition responses elicited by a single vaccine dose in individuals with prior SARS-CoV-2 infection (n = 35) were similar to those seen after two doses of vaccine in individuals without prior infection (n = 228). Post-vaccine symptoms were more prominent for those with prior infection after the first dose, but symptomology was similar between groups after the second dose.

All-dielectric subwavelength metasurface focusing lens.

We have proposed, designed, manufactured and tested low loss dielectric micro-lenses for infrared (IR) radiation based on a dielectric metamaterial layer. This metamaterial layer was created by patterning a dielectric surface and etching to sub-micron depths. For a proof-of-concept lens demonstration, we have chosen a fine patterned array of nano-pillars with variable diameters.

Combination HCV core antigen and antibody assay on a fully automated chemiluminescence analyzer.

Background: HCV exposure among blood donors is serologically determined by detection of antibodies to HCV (anti-HCV); however, the recent development of an assay for the detection of HCV core antigen identifies infection before anti-HCV development. Simultaneous detection of HCV core antigen and anti-HCV would shorten the window period before seroconversion over conventional HCV antibody screening assays.

Study Design And Methods: A prototype chemiluminescent immunoassay was developed for simultaneous detection of HCV core antigen and anti-HCV in human sera and plasma.

Detection of HCV core antigen in human serum and plasma with an automated chemiluminescent immunoassay.

Background: Currently, the detection of HCV infection in blood donors relies on the ability of immunoassays to detect circulating HCV antibodies. However, a significant delay exists between the time of infection and the development of antibodies. This delay (window period) can last up to 70 days.