COVID-19 Vaccine Booster Dose Fails to Enhance Antibody Response to Omicron Variant in Reinfected Healthcare Workers.

The emergence of new variants and diverse vaccination regimens have raised uncertainty about vaccine effectiveness against SARS-CoV-2. This study aims to investigate the impact of Omicron primo-/reinfection and primary vaccination schedules on the immunogenicity of an mRNA-based booster dose over a six-month period. We conducted a prospective cohort study to assess the durability and level of antibodies of 678 healthcare workers fully vaccinated against COVID-19.

Hedgerows interact with forests to shape the abundance of mesopredators and their predation rate on eggs in farmland landscapes.

Nest predation is the main cause of reproductive failure, particularly in ground-nesting birds on farmlands. Understanding the links between nest predation and habitat change can help design effective management schemes to constrain the negative impact of predation pressure on birds. However, the mechanisms underlying the relationships between landscape attributes, predator distribution, and nest predation are still unclear.

Clinical utility of an antibody-free LC-MS method to detect brain amyloid deposition in cognitively unimpaired individuals from the screening visit of the A4 Study.

Introduction: This study explored the ability of plasma amyloid beta (Aβ)42/Aβ40 to identify brain amyloid deposition in cognitively unimpaired (CU) individuals.

Methods: Plasma Aβ was quantified with an antibody-free high-performance liquid chromatography tandem mass spectrometry method from Araclon Biotech (ABtest-MS) in a subset of 731 CU individuals from the screening visit of the Anti-Amyloid Treatment in Asymptomatic Alzheimer's (A4) Study, to assess associations of Aβ42/Aβ40 with Aβ positron emission tomography (PET).

Results: A model including Aβ42/Aβ40, age, apolipoprotein E ε4, and recruitment site identified Aβ PET status with an area under the curve of 0.

Clinical performance of an antibody-free assay for plasma Aβ42/Aβ40 to detect early alterations of Alzheimer's disease in individuals with subjective cognitive decline.

Background: Accessible and cost-effective diagnostic tools are urgently needed to accurately quantify blood biomarkers to support early diagnosis of Alzheimer's disease (AD). In this study, we investigated the ability of plasma amyloid-beta (Aβ)42/Aβ40 ratio measured by an antibody-free mass-spectrometric (MS) method, ABtest-MS, to detect early pathological changes of AD.

Methods: This cohort study included data from the baseline and 2-year follow-up visits from the Fundació ACE Healthy Brain Initiative (FACEHBI) study.

Humoral and cellular immune response over 9 months of mRNA-1273, BNT162b2 and ChAdOx1 vaccination in a University Hospital in Spain.

Scarce data have been reported about cellular immunity and longevity for different COVID-19 vaccination schedules. We carried out a prospective study enrolling 709 healthcare workers receiving two doses of mRNA-1273, BNT162b2, ChAdOx1, ChAdOx1/BNT162b2 or ChAdOx1 single dose to compare humoral and cellular immunogenicity across 9 months. Higher SARS-CoV-2 spike antibody levels were observed among individuals with hybrid immunity with one dose of any vaccine in comparison to uninfected individuals receiving two doses (mRNA-1273: 20,145 vs 4295 U/mL; BNT162b2: 15,659 vs 1959 U/mL; ChAdOx1: 5344 vs 2230 U/mL), except for ChAdOx1/BNT162b2 heterologous schedule (12,380 U/mL).