Boosting Oxygen Reduction Reaction Selectivity in Metal Nanoparticles with Polyoxometalates.

The lack of selectivity toward the oxygen reduction reaction (ORR) in metal nanoparticles can be linked to the generation of intermediates. This constitutes a crucial constraint on the performance of specific electrochemical devices, such as fuel cells and metal-air batteries. To boost selectivity of metal nanoparticles, a novel methodology that harnesses the unique electrocatalytic properties of polyoxometalates (POM) to scavenge undesired intermediates of the ORR (such as HO2 -) promoting selectivity is proposed. It involves the covalent functionalization of metal nanoparticle's surface with an electrochemically active capping layer containing a new sulfur-functionalized vanadium-based POM (AuNP@POM). To demonstrate this approach, preformed thiolate Au(111) nanoparticles with a relatively poor ORR selectivity are chosen. The dispersion of AuNP@POM on the surface of carbon nanofibers (CNF) enhances oxygen diffusion, and therefore the ORR activity. The resulting electrocatalyst (AuNP@POM/CNF) exhibits superior stability against impurities like methanol and a higher pH tolerance range compared to the standard commercial Pt/C. The work demonstrates for the first time, the use of a POM-based electrochemically active capping layer to switch on the selectivity of poorly selective gold nanoparticles, offering a promising avenue for the preparation of electrocatalyst materials with improved selectivity, performance, and stability for ORR-based devices.

Evaluation of 9 IOL power calculation formulas using a heteroscedastic statistical method and a new method of IOL constant optimization.

PURPOSE: To evaluate the prediction accuracy of 9 IOL power calculation formulas using a heteroscedastic statistical analysis and a novel method for IOL constant optimization. DESIGN: Retrospective case series. METHODS: The LenStar LS900 (Haag-Streit, Koeniz, Switzerland) was used for the preoperative biometry. The predicted SE refraction of the implanted IOL were calculated for: Barrett Universal II, EVO-2.0, Hill RBF-3.0, Hill-RBF 2.0, Kane, PEARL-DGS, SRK-T, Hoffer-Q and Holladay-1. IOL constants were optimized prior to the analysis. A heteroscedastic statistical method was used to compare the standard deviation (SD) of prediction errors (PE). RESULTS: Two hundred seventy-eight eyes of 278 patients were included. The SD of the Kane was 0.4214D and was the lowest in this database. The SD of the PE of the Kane and EVO 2.0 were significantly lower than the SRK-T, Holladay 1, and Hoffer-Q. The SD of the PE of the PEARL formula was significantly lower than the SRK-T and Hoffer-Q. The SD of the PE of the Hill-RBF 3.0 was not significantly different to the Hill-RBF 2.0, Kane, EVO 2.0, Barrett Universal II and PEARL. No significant difference was found between the SD of the PE of the new generation formulas analysed. CONCLUSIONS: the lowest SD of the prediction error was provided by Kane, followed by EVO 2.0 and PERL-DGS formulas. However, no statistically significant differences were found between the SD of the PE of new generation formulas. Further studies are necessary to evaluate the accuracy of these formulas in extreme eyes.

Usefulness of inclusion of ertapenem and temocillin screening breakpoints in the EUCAST rapid antimicrobial susceptibility testing (RAST) for rapid detection of OXA-48-producing Klebsiella pneumoniae directly from positive blood cultures.

OBJECTIVES: The aims of this study were: (i) to assess the ability of the meropenem screening breakpoint as part of the screening rapid antimicrobial susceptibility testing (sRAST) of EUCAST for the detection of OXA-48 carbapenemase-producing Klebsiella pneumoniae directly from positive blood cultures (BCs); and (ii) to evaluate the inclusion of ertapenem and temocillin discs into the sRAST to enhance the detection of OXA-48-producing isolates. METHODS: BC bottles were spiked with a total of 117 K. pneumoniae isolates, including 77 previously characterized OXA-48 producers and 40 non-OXA-48 producers. Disc diffusion assays were directly performed from positive BCs with meropenem (10 µg), ertapenem (10 µg) and temocillin (30 µg) discs, and inhibition zones were manually measured after 4, 6 and 8 h of incubation. The screening cut-off values of sRAST were applied to evaluate their capability in detecting OXA-48-producing isolates. Receiver operating characteristic curves were constructed to illustrate the performance efficacy of the disc diffusion assays to detect OXA-48 producers. RESULTS: The meropenem cut-off values of sRAST only detected 90.91% of the OXA-48-producing isolates after 6 and 8 h of incubation. With the proposed cut-off points for ertapenem [<19 mm (4/6 h) and <20 mm (8 h)] and temocillin [<10 mm (4 h) and <11 mm (6/8 h)], all OXA-48-positive isolates were detected without any false-positive results at any reading time. CONCLUSIONS: In healthcare settings with a high prevalence of OXA-48 producers, the inclusion of ertapenem and temocillin discs in the sRAST procedure may improve the detection of OXA-48-producing K. pneumoniae isolates directly from positive BCs, providing reliable results after only a 4 h incubation period.

Tomographic Findings in the Retina of Unvaccinated Patients with COVID Pneumonia: Prospective Longitudinal Study.

There is no definitive evidence on the extent of SARS-CoV-2's effect on the retina. This study aims to determine if the natural history of SARS-CoV-2 infection affects tomographic findings in the retina of patients with COVID-19 pneumonia. This is a prospective cohort study of patients hospitalized with COVID-19 pneumonia. The patients underwent ophthalmological explorations and optical coherence tomography during the acute phase of the infection and at a follow-up 12 weeks later. The primary outcomes were the central retinal thickness and central choroidal thickness, which were compared longitudinally and with non-COVID-19 historical controls. No statistically relevant differences were observed in the longitudinal analysis of the thickness of the central retina (p = 0.056), central choroid (p = 0.99), retinal nerve fiber layer (p = 0.21), or ganglion cell layer (p = 0.32). Patients with acute COVID-19 pneumonia showed significantly greater central retinal thickness than non-COVID controls (p = 0.006). In conclusion, tomographic measures of the retina and choroid are not influenced by the phase of COVID-19 infection and remain stable during 12 weeks. The central retinal thickness may increase in the acute phase of COVID-19 pneumonia, but more epidemiological studies using optical coherence tomography in the early stages of the disease are needed.

Marine litter education: From awareness to action.

Marine litter is a global problem. Education has been acclaimed as a potential tool to tackle this issue, yet, integrative, student-centered, and over weeks studies to raise awareness on the theme that compares pre- with post-intervention results are limited in the literature. Furthermore, almost no studies rely on the basis of previous experience on the theme and local reality. This paper presents the design, implementation, and evaluation of an educational intervention to raise awareness and educate students (1st cycle to high-school) about marine litter. Different learning skills were fostered through theoretical, laboratorial, and hands-on activities and students participated in a beach clean-up to summarize the classroom's learnings in loco. Pre- and post-questionnaire results indicate that students' knowledge, perceptions, and behavioral intentions changed. Identification of marine litter estimated degradation times and observation of microplastics in local sand samples were activities highly appreciated by youngsters. This intervention positively impacted schoolchildren's literacy, contributing to advancing education in marine litter and can be further adapted to other educational areas.

Enterococcal Phages: Food and Health Applications.

Enterococcus is a diverse genus of Gram-positive bacteria belonging to the lactic acid bacteria (LAB) group. It is found in many environments, including the human gut and fermented foods. This microbial genus is at a crossroad between its beneficial effects and the concerns regarding its safety. It plays an important role in the production of fermented foods, and some strains have even been proposed as probiotics. However, they have been identified as responsible for the accumulation of toxic compounds-biogenic amines-in foods, and over the last 20 years, they have emerged as important hospital-acquired pathogens through the acquisition of antimicrobial resistance (AMR). In food, there is a need for targeted measures to prevent their growth without disturbing other LAB members that participate in the fermentation process. Furthermore, the increase in AMR has resulted in the need for the development of new therapeutic options to treat AMR enterococcal infections. Bacteriophages have re-emerged in recent years as a precision tool for the control of bacterial populations, including the treatment of AMR microorganism infections, being a promising weapon as new antimicrobials. In this review, we focus on the problems caused by Enterococcus faecium and Enterococcus faecalis in food and health and on the recent advances in the discovery and applications of enterococcus-infecting bacteriophages against these bacteria, with special attention paid to applications against AMR enterococci.

Electrochemically Versatile Graphite Nanoplatelets Prepared by a Straightforward, Highly Efficient, and Scalable Route.

Nanostructured carbon materials with tailor-made structures (e.g., morphology, topological defect, dopant, and surface area) are of significant interest for a variety of applications. However, the preparation method selected for obtaining these tailor-made structures determines the area of application, precluding their use in other technological areas of interest. Currently, there is a lack of simple and low-cost methodologies versatile enough for obtaining freestanding carbon nanostructures that can be used in either energy storage or chemical detection. Here, a novel methodology for the development of a versatile electrochemically active platform based on freestanding graphite nanoplatelets (GNP) has been developed by exploiting the interiors of hollow carbon nanofibers (CNF) comprising nanographene stacks using dry ball-milling. Even though ball-milling could be considered as a universal method for any carbonaceous material, often, it is not as simple (one step, no purification, and no solvents), efficient (just GNP without tubular structures), and quick (just 20 min) as the sustainable method developed in this work, free of surfactants and stabilizer agents. We demonstrate that the freestanding GNP developed in this work (with an average thickness of 3.2 nm), due to the selective edge functionalization with the minimal disruption of the basal plane, can act either as a supercapacitor or as a chemical sensor, showing both a dramatic improvement in the charge storage ability of more than 30 times and an enhanced detection of electrochemically active molecules such as ascorbic acid with a 236 mV potential shift with respect to CNF in both cases. As shown here, GNP stand as an excellent versatile alternative compared to the standard commercially available carbon-based materials. Overall, our approach paves the way for the discovery of new nanocarbon-based electrochemical active platforms with a wide electrochemical applicability.

Enterococcus faecium Bacteriophage vB_EfaH_163, a New Member of the Herelleviridae Family, Reduces the Mortality Associated with an E. faecium vanR Clinical Isolate in a Galleria mellonella Animal Model.

The rise of antimicrobial resistant (AMR) bacteria is a major health concern, especially with regard to members of the ESKAPE group, to which vancomycin-resistant (VRE) Enterococcus faecium belongs. Phage therapy has emerged as a novel alternative for the treatment of AMR infections. This, however, relies on the isolation and characterisation of a large collection of phages. This work describes the exploration of human faeces as a source of new E. faecium-infecting phages. Phage vB_EfaH_163 was isolated and characterised at the microbiological, genomic, and functional levels. vB_EfaH_163 phage, a new member of Herelleviridae, subfamily Brockvirinae, has a dsDNA genome of 150,836 bp that does not harbour any virulence factors or antibiotic resistance genes. It infects a wide range of E. faecium strains of different origins, including VRE strains. Interestingly, it can also infect Enterococcus faecalis strains, even some that are linezolid-resistant. Its capacity to control the growth of a clinical VRE isolate was shown in broth culture and in a Galleria mellonella animal model. The discovery and characterisation of vB_EfaH_163 increases the number of phages that might be used therapeutically against AMR bacteria.

Magnetic Hyperthermia Enhancement in Iron-based Materials Driven by Carbon Support Interactions.

Magnetic hyperthermia (MH) shows great potential in clinical applications because of its very localized action and minimal side effects. Because of their high saturation magnetization values, reduced forms of iron are promising candidates for MH. However, they must be protected in order to overcome their toxicity and instability (i. e., oxidation) under biological conditions. In this work, a novel methodology for the protection of iron nanoparticles through confinement within graphitic carbon layers after thermal treatment of preformed nanoparticles supported on carbon is reported. We demonstrate that the size and composition of the nascent confined iron nanoparticles, as well as the thickness of their protective carbon layer can be controlled by selecting the nature of the carbon support. Our findings reveal that a higher nanoparticle-carbon interaction, mediated by the presence of oxygen-containing groups, induces the formation of small and well-protected α-Fe-based nanoparticles that exhibit promising results towards MH based on their enhanced specific absorption rate values.

Detection of the optrA Gene Among Polyclonal Linezolid-Susceptible Isolates of Enterococcus faecalis Recovered from Community Patients.

Dispersion of transferable oxazolidinone resistance genes among enterococci poses a serious problem to human health. Prompt detection of bacteria carrying these genes is crucial to avoid their spread to multidrug-resistant bacteria. The aim of the study was to describe the presence of optrA-positive isolates among enterococci in a Spanish hospital, and to determine their genetic context and location through whole genome sequencing. All enterococci recovered in a Spanish hospital (Hospital El Bierzo; HEB) from February to December 2018 (n = 443), with minimal inhibitory concentrations (MICs) to linezolid (LZD) ≥4 mg/L, were tested by polymerase chain reaction for the presence of cfr, optrA, and poxtA transferable genes. Only four Enterococcus faecalis isolates (0.9%) had LZD MICs ≥4 mg/L and none of them was positive for cfr or poxtA genes. However, the optrA gene was detected in three isolates collected from urine samples of community patients, whose genomes were sequenced and subjected to bioinformatics analysis. These isolates belonged to different clones: ST7, ST480, and ST585. In these three isolates, the optrA gene was located on plasmids, associated with IS1216 in different arrays. In one isolate, the optrA plasmid coexists with a second plasmid, which carried multiple resistance genes for different classes of antibiotics. Detection of optrA-positive E. faecalis isolates in the community is a matter of concern. The spread of these bacteria into hospital settings, particularly in those, such as the HEB, where vancomycin-resistant enterococci are endemic, should be avoided, to preserve the efficacy of the last-resort oxazolidinones.

Intraobserver Repeatability of Tomographic, Pachymetric, and Anatomical Measurements in Healthy Eyes Using a New Swept-Source Optical Coherence Topographer.

PURPOSE: The purpose of this study was to evaluate the intraobserver repeatability of several corneal parameters in healthy eyes using a new swept-source optical coherence topographer. METHODS: Fifty right eyes of 50 subjects were enrolled in this study. A single examiner performed 3 consecutive measurements using the Anterion swept-source optical coherence tomography. The following corneal parameters were evaluated: average keratometry (K), steep K, flat K, astigmatism, best fit sphere, and maximum keratometry on the anterior and posterior surfaces at 3 mm, average K, steep K, flat K, and astigmatism in the total corneal power map at 3 mm, central corneal thickness and thinnest point thickness in the pachymetric map, and corneal diameter. To assess the repeatability of the measurements, we calculated the following indexes: intrasubject SD (Sw), coefficient of variation, coefficient of repeatability, and intraclass correlation coefficient (ICC). RESULTS: High repeatability was reported for all the evaluated corneal parameters, with Sw values lower than 0.027, coefficient of variation values lower than 0.066%, and coefficient of repeatability values lower than 0.187. ICC values showed a high correlation between measurements in all cases, being the lowest value for the astigmatism of the anterior surface (ICC = 0.92); for the rest, ICC values were larger than 0.98. Finally, we have not found statistically significant differences between repeated measurements (P > 0.05). CONCLUSIONS: The anterior segment measurements provided by the Anterion swept-source optical coherence tomography device show high intraobserver repeatability in healthy eyes.

Spread of Gamma (P.1) Sub-Lineages Carrying Spike Mutations Close to the Furin Cleavage Site and Deletions in the N-Terminal Domain Drives Ongoing Transmission of SARS-CoV-2 in Amazonas, Brazil.

The Amazonas was one of the most heavily affected Brazilian states by the COVID-19 epidemic. Despite a large number of infected people, particularly during the second wave associated with the spread of the Variant of Concern (VOC) Gamma (lineage P.1), SARS-CoV-2 continues to circulate in the Amazonas. To understand how SARS-CoV-2 persisted in a human population with a high immunity barrier, we generated 1,188 SARS-CoV-2 whole-genome sequences from individuals diagnosed in the Amazonas state from 1st January to 6th July 2021, of which 38 were vaccine breakthrough infections. Our study reveals a sharp increase in the relative prevalence of Gamma plus (P.1+) variants, designated Pango Lineages P.1.3 to P.1.6, harboring two types of additional Spike changes: deletions in the N-terminal (NTD) domain (particularly Δ144 or Δ141-144) associated with resistance to anti-NTD neutralizing antibodies or mutations at the S1/S2 junction (N679K or P681H) that probably enhance the binding affinity to the furin cleavage site, as suggested by our molecular dynamics simulations. As lineages P.1.4 (S:N679K) and P.1.6 (S:P681H) expanded (Re > 1) from March to July 2021, the lineage P.1 declined (Re < 1) and the median Ct value of SARS-CoV-2 positive cases in Amazonas significantly decreases. Still, we did not find an increased incidence of P.1+ variants among breakthrough cases of fully vaccinated patients (71%) in comparison to unvaccinated individuals (93%). This evidence supports that the ongoing endemic transmission of SARS-CoV-2 in the Amazonas is driven by the spread of new local Gamma/P.1 sublineages that are more transmissible, although not more efficient to evade vaccine-elicited immunity than the parental VOC. Finally, as SARS-CoV-2 continues to spread in human populations with a declining density of susceptible hosts, the risk of selecting more infectious variants or antibody evasion mutations is expected to increase. IMPORTANCE The continuous evolution of SARS-CoV-2 is an expected phenomenon that will continue to happen due to the high number of cases worldwide. The present study analyzed how a Variant of Concern (VOC) could still circulate in a population hardly affected by two COVID-19 waves and with vaccination in progress. Our results showed that the answer behind that was a new generation of Gamma-like viruses, which emerged locally carrying mutations that made it more transmissible and more capable of spreading, partially evading prior immunity triggered by natural infections or vaccines. With thousands of new cases daily, the current pandemics scenario suggests that SARS-CoV-2 will continue to evolve and efforts to reduce the number of infected subjects, including global equitable access to COVID-19 vaccines, are mandatory. Thus, until the end of pandemics, the SARS-CoV-2 genomic surveillance will be an essential tool to better understand the drivers of the viral evolutionary process.

Time-dependent evolution of IgG antibody levels after first and second dose of mRNA-based SARS-CoV-2 vaccination in haemodialysis patients: a multicentre study.

BACKGROUND: Vaccination programs are essential for the containment of the coronavirus disease 2019 pandemic, which has hit haemodialysis populations especially hard. Early reports suggest a reduced immunologic response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in dialysis patients, in spite of a high degree of seroconversion. We aimed to identify risk factors for a reduced efficacy of an mRNA vaccine in a cohort of haemodialysis patients. METHOD: In a multicentre study, including 294 Portuguese haemodialysis patients who had received two doses of BNT162b2 with a 3-week interval, immunoglobulin G-class antibodies against the SARS-CoV-2 spike protein were determined 3 weeks after the first dose (M1) and 6 weeks after the second dose (M2). The threshold for seroconversion was 10 UR/mL. Demographic and clinical data were retrieved from a quality registry. Adverse events were registered using a questionnaire. RESULTS: At M2, seroconversion was 93.1% with a median antibody level of 197.5 U/mL (1.2-3237.0) and a median increase of 180.0 U/mL (-82.9 to 2244.6) from M1. Age [beta -8.9; 95% confidence interval (95% CI) -12.88 to -4.91; P < 0.0001], ferritin >600 ng/mL (beta 183.93; 95% CI 74.75-293.10; P = 0.001) and physical activity (beta 265.79; 95% CI 30.7-500.88; P = 0.03) were independent predictors of SARS-CoV-2 antibody levels after two vaccine doses. Plasma albumin >3.5 g/dL independently predicted the increase of antibody levels between both doses (odds ratio 14.72; 95% CI 1.38 to 157.45; P = 0.03). Only mild adverse reactions were observed in 10.9% of patients. CONCLUSIONS: The SARS-CoV-2 vaccine BNT162b2 is safe and effective in haemodialysis patients. Besides age, iron status and nutrition are possible modifiable modulators of the immunologic response to SARS-CoV-2 mRNA vaccines. These data suggest the need for an early identification of populations at higher risk for diminished antibody production and the potential advantage of the implementation of oriented strategies to maximize the immune response to vaccination in these patients.

Establishment and Persistence of Glycopeptide-Resistant Enterococcus faecium ST80 and ST117 Clones Within a Health Care Facility Located in a Low-Prevalence Geographical Region.

Vancomycin-resistant Enterococcus faecium (VREfm) is one of the most important nosocomial pathogens with limited therapeutic alternatives. In this study, we followed the trends of VREfm and E. faecium causing bloodstream infections (BSIs) in a Spanish hospital, from 2011 to 2020. During this period, 832 E. faecium strains were isolated and 121 (14.5%) were vancomycin resistant. Nineteen of 101 BSIs (18.8%) caused by E. faecium were due to VREfm. The number of BSI-producing E. faecium isolates increased significantly over the past 5 years, with the percentage of invasive VREfm isolates being substantially higher than the average values in Europe and especially in Spain (<3%). VREfm isolates recovered in 2018 (28) and BSI-producing isolates from 2019 (3) and 2020 (2) were molecularly characterized. All were positive for vanA and belonged to sequence type (ST) 80 (28) or ST117 (5), within clonal complex 17. The isolates were only susceptible to linezolid, although most of them were also susceptible (dose dependent) to daptomycin. We report for the first time the establishment and persistence of the VREfm ST80 and ST117 clones in a Spanish hospital. The spread and establishment of hospital-adapted, multidrug-resistant VREfm clones in health care settings are cause for concern and may precede an increment in the BSIs caused by them.

Immunogenicity and tolerability of COVID-19 vaccination in peritoneal dialysis patients-A prospective observational cohort study.

BACKGROUND: In peritoneal dialysis (PD) patients, information on the immunogenicity and tolerability of SARS-CoV-2 vaccination is still scarce. We compared the immunogenicity and tolerability of SARS-CoV-2 vaccination of PD patients with that of medical personnel. METHODS: In a prospective observational cohort study, PD patients and immunocompetent medical personnel were evaluated for SARS-CoV-2 spike-IgG- and Nucleocapsid-IgG-antibody-levels before, 2 weeks after the first, and 6 weeks after the second SARS-CoV-2 vaccination and vaccine tolerability after the first and second vaccination. RESULTS: In COVID-19-naïve PD patients (N = 19), lower SARS-CoV-2-spike-IgG-levels were found compared with COVID-19-naïve medical personnel (N = 24) 6 weeks after second vaccination (median 1438 AU/ml [25th-75th percentile 775-5261] versus 4577 [1529-9871]; p = 0.045). This finding resulted in a lower rate of strong vaccine response (spike-IgG ≥ 1000 AU/ml) of COVID-19-naïve PD patients compared with medical personnel (58% versus 92%; p = 0.013), but not for seroconversion rate (spike-IgG ≥ 50 AU/ml: 100% vs. 100%; p > 0.99). After first vaccination, COVID-naïve PD patients presented with significantly fewer side effects than medical personnel (number of any side effect: 1 [1-2] vs. 4 [1-7]; p = 0.015). A similar pattern with slightly decreased frequencies of side effects was observed for tolerability of second SARS-CoV-2 vaccination in PD patients and medical personnel (number of any side effects: 1 [1-1] vs. 2 [1-5]; p = 0.006). CONCLUSIONS: SARS-CoV-2 vaccination in COVID-19-naïve PD patients appeared to induce a very high rate of seroconversion but a substantially lower rate of patients with a strong response compared with medical personnel. Vaccination appeared to be safe in the PD patients studied.

Workforce Readiness Training: A Comprehensive Training Model That Equips Community Health Workers to Work at the Top of Their Practice and Profession.

Background: Recent reports have recognized that only 20 percent of health outcomes are attributed to clinical care. Environmental conditions, behaviors, and social determinants of health account for 80 percent of overall health outcomes. With shortages of clinical providers stressing an already burdened healthcare system, Community Health Workers (CHWs) can bridge healthcare gaps by addressing these nonmedical factors influencing health. This paper details how a comprehensive training model equips CHWs for workforce readiness so they can perform at the top of their practice and profession and deliver well-coordinated client/patient-centered care. Methods: Literature reviews and studies revealed that training CHWs alone is not sufficient for successful workforce readiness, rather CHW integration within the workforce is needed. Consequently, this comprehensive training model is developed for CHWs with varying skill levels and work settings, and supervisors to support organizational readiness and CHW integration efforts. A systematic training program development approach along with detailed implementation methods are presented. Continuing education sessions to support CHW practice and Organizational Readiness Training for supervisors, leadership and team members directly engaged with CHWs in the workplace are also discussed. CHWs were involved in all phases of the research, development, implementation, and actively serve in evaluations and curriculum review committees. Results: Components of the comprehensive training model are presented with an emphasis on the core CHW training. Two CHW training tracks are offered using three delivery modalities. Process measures with student learning objectives, outcome measures developed using the Kirkpatrick model to capture attitude, perceptions, knowledge acquisition, confidence, behavior, and overall experience, and impact stories by two CHWs are presented. Lessons learned from the implementation of the training program are discussed in three categories: Practice-driven curricula, student-centered training implementation, and adaptations in response to COVID-19 pandemic. Conclusion: This comprehensive training model recognizes that training CHWs in a robust training program is key as the demand for well-rounded CHWs increases. Furthermore, a comprehensive training program must include training for supervisors, leadership, and team members working directly with CHWs. Such efforts strengthen the CHW practice and profession to support the delivery of well-coordinated and holistic client/patient-centered care.

Immunogenicity of a first dose of mRNA- or vector-based SARS-CoV-2 vaccination in dialysis patients: a multicenter prospective observational pilot study.

BACKGROUND: Dialysis patients are at risk for lower SARS-CoV-2-vaccine immunogenicity than the normal population. We assessed immunogenicity to a first mRNA- or vector-based SARS-CoV-2-vaccination dose in dialysis patients. METHODS: In a multicenter observational pilot study, 2 weeks after a first vaccination (BNT162b2/Pfizer-BioNTech [Comirnaty] or ChAdOx1 nCoV-19/Oxford-Astra-Zeneca [Vaxzevria]), hemodialysis patients (N = 23), peritoneal dialysis patients (N = 4) and healthy staff (N = 14) were tested for SARS-CoV-2-spike IgG/IgM, Nucleocapsid-protein-IgG-antibodies and plasma ACE2-receptor-binding-inhibition capacity. Hemodialysis patients who had had prior COVID-19 infection (N = 18) served as controls. Both response to first SARS-CoV-2 vaccination and IgG spike-positivity following prior COVID-19 infection were defined as SARS-CoV-2 spike IgG levels ≥ 50 AU/mL. RESULTS: Vaccination responder rates were 17.4% (4/23) in hemodialysis patients, 100% (4/4) in peritoneal dialysis patients and 57.1% (8/14) in staff (HD vs. PD: p = 0.004, HD vs. staff: p = 0.027). Among hemodialysis patients, type of vaccine (Comirnaty N = 11, Vaxzevria N = 12, 2 responders each) did not appear to influence antibody levels (IgG spike: Comirnaty median 0.0 [1.-3. quartile 0.0-3.8] versus Vaxzevria 4.3 [1.6-20.1] AU/mL, p = 0.079). Of responders to the first dose of SARS-CoV-2 vaccination among hemodialysis patients (N = 4/23), median IgG spike levels and ACE2-receptor-binding-inhibition capacity were lower than that of IgG spike-positive hemodialysis patients with prior COVID-19 infection (13/18, 72.2%): IgG spike: median 222.0, 1.-3. quartile 104.1-721.9 versus median 3794.6, 1.-3. quartile 793.4-9357.9 AU/mL, p = 0.015; ACE2-receptor-binding-inhibition capacity: median 11.5%, 1.-3. quartile 5.0-27.3 versus median 74.8%, 1.-3. quartile 44.9-98.1, p = 0.002. CONCLUSIONS: Two weeks after their first mRNA- or vector-based SARS-CoV-2 vaccination, hemodialysis patients demonstrated lower antibody-related response than peritoneal dialysis patients and healthy staff or unvaccinated hemodialysis patients following prior COVID-19 infection.

Risk prediction of COVID-19 incidence and mortality in a large multi-national hemodialysis cohort: implications for management of the pandemic in outpatient hemodialysis settings.

BACKGROUND: Experiences from the first wave of the 2019 coronavirus disease (COVID-19) pandemic can aid in the development of future preventive strategies. To date, risk prediction models for COVID-19-related incidence and outcomes in hemodialysis (HD) patients are missing. METHODS: We developed risk prediction models for COVID-19 incidence and mortality among HD patients. We studied 38 256 HD patients from a multi-national dialysis cohort between 3 March and 3 July 2020. Risk prediction models were developed and validated, based on predictors readily available in outpatient HD units. We compared mortality among patients with and without COVID-19, matched for age, sex and diabetes. RESULTS: During the observational period, 1259 patients (3.3%) acquired COVID-19. Of these, 62% were hospitalized or died. Mortality was 22% among COVID-19 patients with odds ratios 219.8 [95% confidence interval (CI) 80.6-359] to 342.7 (95% CI 60.6-13 595.1), compared to matched patients without COVID-19. Since the first wave of the pandemic affected most European countries during the study, the risk prediction model for incidence of COVID-19 was developed and validated in European patients only [N = 22 826 area under the ROC curve(AUC)Dev 0.64, AUCVal 0.69]. The model for prediction of mortality was developed in all COVID-19 patients (AUCDev 0.71, AUCVal 0.78). Angiotensin receptor blockers were independently associated with a lower incidence of COVID-19 in European patients. CONCLUSIONS: We identified modifiable risk factors for COVID-19 incidence and outcome in HD patients. Our risk prediction tools can be readily applied in clinical practice. This can aid in the development of preventive strategies for future waves of COVID-19.