SARS-CoV-2 Antibody Dynamics in Healthcare Workers after mRNA Vaccination.

Since the emergence of SARS-CoV-2, maintaining healthcare worker (HCW) health and safety has been fundamental to responding to the global pandemic. Vaccination with mRNA-base vaccines targeting SARS-CoV-2 spike protein has emerged as a key strategy in reducing HCW susceptibility to SARS-CoV-2, however, neutralizing antibody responses subside with time and may be influenced by many variables. We sought to understand the dynamics between vaccine products, prior clinical illness from SARS-CoV-2, and incidence of vaccine-associated adverse reactions on antibody decay over time in HCWs at a university medical center. A cohort of 296 HCWs received standard two-dose vaccination with either bnt162b2 (Pfizer/BioNTech) or mRNA-1273 (Moderna) and were evaluated after two, six, and nine months. Subjects were grouped by antibody decay curve into steep antibody decliners gentle decliners. Vaccination with mRNA-1273 led to more sustained antibody responses compared to bnt162b2. Subjects experiencing vaccine-associated symptoms were more likely to experience a more prolonged neutralizing antibody response. Subjects with clinical SARS-CoV-2 infection prior to vaccination were more likely to experience vaccination-associated symptoms after first vaccination and were more likely to have a more blunted antibody decay. Understanding factors associated with vaccine efficacy may assist clinicians in determining appropriate vaccine strategies in HCWs.

Deep dissection of the antiviral immune profile of patients with COVID-19.

In light of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants potentially undermining humoral immunity, it is important to understand the fine specificity of the antiviral antibodies. We screened 20 COVID-19 patients for antibodies against 9 different SARS-CoV-2 proteins observing responses against the spike (S) proteins, the receptor-binding domain (RBD), and the nucleocapsid (N) protein which were of the IgG1 and IgG3 subtypes. Importantly, mutations which typically occur in the B.1.351 "South African" variant, significantly reduced the binding of anti-RBD antibodies. Nine of 20 patients were critically ill and were considered high-risk (HR). These patients showed significantly higher levels of transforming growth factor beta (TGF-ß) and myeloid-derived suppressor cells (MDSC), and lower levels of CD4+ T cells expressing LAG-3 compared to standard-risk (SR) patients. HR patients evidenced significantly higher anti-S1/RBD IgG antibody levels and an increased neutralizing activity. Importantly, a large proportion of S protein-specific antibodies were glycosylation-dependent and we identified a number of immunodominant linear epitopes within the S1 and N proteins. Findings derived from this study will not only help us to identify the most relevant component of the anti-SARS-CoV-2 humoral immune response but will also enable us to design more meaningful immunomonitoring methods for anti-COVID-19 vaccines.

SARS-CoV-2 specific antibody and neutralization assays reveal the wide range of the humoral immune response to virus.

Development of antibody protection during SARS-CoV-2 infection is a pressing question for public health and for vaccine development. We developed highly sensitive SARS-CoV-2-specific antibody and neutralization assays. SARS-CoV-2 Spike protein or Nucleocapsid protein specific IgG antibodies at titers more than 1:100,000 were detectable in all PCR+ subjects (n = 115) and were absent in the negative controls. Other isotype antibodies (IgA, IgG1-4) were also detected. SARS-CoV-2 neutralization was determined in COVID-19 and convalescent plasma at up to 10,000-fold dilution, using Spike protein pseudotyped lentiviruses, which were also blocked by neutralizing antibodies (NAbs). Hospitalized patients had up to 3000-fold higher antibody and neutralization titers compared to outpatients or convalescent plasma donors. Interestingly, some COVID-19 patients also possessed NAbs against SARS-CoV Spike protein pseudovirus. Together these results demonstrate the high specificity and sensitivity of our assays, which may impact understanding the quality or duration of the antibody response during COVID-19 and in determining the effectiveness of potential vaccines.

Novel SARS-CoV-2 specific antibody and neutralization assays reveal wide range of humoral immune response during COVID-19.

Development of antibody protection during SARS-CoV-2 infection is a pressing question for public health and for vaccine development. We developed highly sensitive SARS-CoV-2-specific antibody and neutralization assays. SARS-CoV-2 Spike protein or Nucleocapsid protein specific IgG antibodies at titers more than 1:100,000 were detectable in all PCR+ subjects (n=115) and were absent in the negative controls. Other isotype antibodies (IgA, IgG1-4) were also detected. SARS-CoV-2 neutralization was determined in COVID-19 and convalescent plasma at up to 10,000-fold dilution, using Spike protein pseudotyped lentiviruses, which were also blocked by neutralizing antibodies (NAbs). Hospitalized patients had up to 3000-fold higher antibody and neutralization titers compared to outpatients or convalescent plasma donors. Interestingly, some COVID-19 patients also possessed NAbs against SARS-CoV Spike protein pseudovirus. Together these results demonstrate the high specificity and sensitivity of our assays, which may impact understanding the quality or duration of the antibody response during COVID-19 and in determining the effectiveness of potential vaccines.

A Propensity Score Matched Study of the Positive Impact of Infectious Diseases Consultation on Antimicrobial Appropriateness in Hospitalized Patients with Antimicrobial Stewardship Oversight.

Hospital-based antibiotic stewardship (AS) programs provide oversight and guidance for appropriate antimicrobial use in acute care settings. Infectious disease expertise is beneficial in the care of hospitalized patients with infections. The impact of infectious diseases consultation (IDC) on antimicrobial appropriateness in a large tertiary hospital with an established AS program was investigated. This was a cross-sectional study from October 2017 to March 2019 at a large academic hospital with an AS-directed prospective audit and feedback process and multiple IDC services. Antimicrobial appropriateness was adjudicated by an AS team member after antimicrobial start. Antimicrobial appropriateness was compared among antimicrobial orders with and without IDC using propensity score matching and multivariable logistic regression. Analyses were stratified by primary services caring for the patients. There were 10,508 antimicrobial orders from 6,165 unique patient encounters. Overall appropriateness was 92%, with higher appropriateness among patients with IDC versus without IDC (94% versus 84%; P < 0.0001). After propensity score matching and adjustment for certain antibiotics, organisms, syndromes, and locations, IDC was associated with a greater antimicrobial appropriateness odds ratio (OR) of 2.4 (95% confidence interval [CI], 1.9 to 3.0). Stratification by primary service showed an OR of 2.9 (95% CI, 2.1 to 3.8) for surgical specialties and an OR of 1.6 (95% CI, 1.1 to 2.2) for medical specialties. Even with a high overall antimicrobial appropriateness, patients with IDC had greater odds of antimicrobial appropriateness than those without IDC, and this impact was greater in surgical specialties. Infectious diseases consultation can be synergistic with antimicrobial stewardship programs.

Peer Comparison of Anti-MRSA Agent Prescription in the Inpatient Setting.

Peer comparison has potential as an effective antimicrobial stewardship intervention in the inpatient setting. We report a new metric, days of therapy per 100 service days, for comparing antibiotic utilization. Among 14 prescribers on the primary infectious diseases service during a 6-month period, we identified 1 outlier for each anti-MRSA agent. Infect Control Hosp Epidemiol 2017;38:1506-1508.

Implementation of an Infectious Disease Fellow-Managed Penicillin Allergy Skin Testing Service.

Background. A large percentage of patients presenting to acute care facilities report penicillin allergies that are associated with suboptimal antibiotic therapy. Penicillin skin testing (PST) can clarify allergy histories but is often limited by access to testing. We aimed to implement an infectious diseases (ID) fellow-managed PST program and to assess the need for PST via national survey. Methods. We conducted a prospective observational study of the implementation of an ID fellow-managed penicillin allergy skin testing service. The primary outcome of the study was to assess the feasibility and acceptability of an ID fellow-managed PST service and its impact on the optimization of antibiotic selection. In addition, a survey of PST practices was sent out to all ID fellowship program directors in the United States. Results. In the first 11 months of the program, 90 patients were assessed for PST and 76 patients were tested. Of the valid tests, 96% were negative, and 84% with a negative test had antibiotic changes; 63% received a narrower spectrum antibiotic, 80% received more effective therapy, and 61% received more cost-effective therapy. The majority of survey of respondents (n = 50) indicated that overreporting of penicillin allergy is a problem in their practice that affects antibiotic selection but listed inadequate personnel and time as the main barriers to PST. Conclusions. Inpatient PST can be successfully managed by ID fellows, thereby promoting optimal antibiotic use in patients reporting penicillin allergies. This model can increase access to PST at institutions without adequate access to allergists while also providing an important educational experience to ID trainees.

Galactomannan antigen detection using bronchial wash and bronchoalveolar lavage in patients with hematologic malignancies.

BACKGROUND: The diagnosis of invasive pulmonary aspergillosis is challenging. It is unclear whether galactomannan (GM) results from bronchial wash (BW) and bronchoalveolar lavage (BAL) samples differ in a clinically meaningful way. RESULTS: Ninety-six paired (BAL and BW) samples from 85 patients were included. The average age was 53 years, 61 % of the patients were male, and 74.1 % had an underlying diagnosis of AML/MDS (ALL 7.1 %, other hematologic malignancy 18.8 %). 57 (67.1 %) patients were neutropenic, and 56 (65.9 %) patients were receiving mold-active drugs at least 48 h prior to bronchoscopy. The overall agreement between GM detection from BW and BAL was 63.5 % (K = 0.152; 95 % CI 0.008-0.311) and 73 % (K = 0.149; 95 % CI 0.048-0.348) at cut off ≥0.5 and ≥1.0, respectively. Among 43 positive samples, using a GM cut-off of 0.5, 39 (90.5 %) were positive in BW samples whereas 12 (29.3 %) were positive in BAL samples. The median level of GM in BW (0.28) samples was significantly higher than in BAL (0.20) samples among 53 samples with negative results (P = 0.001). There was no statistically significant difference in the median GM values between the BW and BAL samples with positive results (P = 0.08). There was no significant difference in GM detection between samples with positive and negative results with regard to antifungal, beta lactam antibacterial treatment or neutropenia (60.5 vs 56.6 %; 53.9 vs 46 %; 65.1 vs 54.7 %, respectively). CONCLUSION: This retrospective study examining two collection techniques suggests that BW may have higher diagnostic yield compared to bronchoalveolar lavage for GM detection.

Hybrid III Lower Leg Injury Assessment Reference Curves Under Axial Impacts Using Matched-Pair Tests.

The objective of the present study was to derive injury probability curves applicable to the Hybrid III dummy (also termed the Anthropomorphic Test Device, ATD) lower leg under axial impacts for military applications. A matched-pair approach was used. Axial impacts were delivered to below knee foot-ankle complex preparations of the lower leg of the ATD using pendulum and custom vertical accelerator devices. Military boot was used in some tests. Post mortem human surrogate (PMHS) preparations were used as matched-pair tests for injury outcomes. The alignment was such that the foot-ankle complex was orthogonal to the leg (below knee tibia-fibula complex), termed as the normal 90-90 posture. Injury outcomes from the biological surrogate focused on calcaneus and or distal tibia fractures with or without the involvement of articular surfaces. Peak lower tibia load cell forces were obtained from matched-pair dummy tests. Injury and force data were paired, censoring was assigned based on injury outcomes and survival analysis was done using the Weibull distribution to derive dummy-based probability curves. Mean peak forces were extracted at 5, 10, 20 and 50% probability levels. Normalized confidence interval sizes (NCIS) at ± 95% level were computed to determine the tightness-of-fit of the confidence bands. The NCIS data ranged from 0.34 to 0.78 and a peak force of 8.2 kN was associated at the ten percent injury probability level. Other data and curves are given in the body of the paper. The present Injury Assessment Reference Curves and Values (IARC and IARV) may be used in future tests for advancing safety in military environments. These survival analysis processes and IARC and IARV data may also be used in other applications.

Prior colonization is associated with increased risk of antibiotic-resistant Gram-negative bacteremia in cancer patients.

We hypothesized that prior colonization with antibiotic-resistant Gram-negative bacteria is associated with increased risk of subsequent antibiotic-resistant Gram-negative bacteremia among cancer patients. We performed a matched case-control study. Cases were cancer patients with a blood culture positive for antibiotic-resistant Gram-negative bacteria. Controls were cancer patients with a blood culture not positive for antibiotic-resistant Gram-negative bacteria. Prior colonization was defined as any antibiotic-resistant Gram-negative bacteria in surveillance or non-sterile-site cultures obtained 2-365 days before the bacteremia. Thirty-two (37%) of 86 cases and 27 (8%) of 323 matched controls were previously colonized by any antibiotic-resistant Gram-negative bacteria. Prior colonization was strongly associated with antibiotic-resistant Gram-negative bacteremia (odds ratio [OR] 7.2, 95% confidence interval [CI] 3.5-14.7) after controlling for recent treatment with piperacillin-tazobactam (OR 2.5, 95% CI 1.3-4.8). In these patients with suspected bacteremia, prior cultures may predict increased risk of antibiotic-resistant Gram-negative bacteremia.

Infection prevention in the cancer center.

Cancer patients are frequently immunosuppressed and at risk for a wide range of opportunistic and healthcare-associated infections. A good infection prevention program is extremely important to reduce risk of infection. This review focuses on infection prevention measures specific to patients, healthcare personnel, and visitors in the cancer center.

Regulation of hyperoxia-induced NADPH oxidase activation in human lung endothelial cells by the actin cytoskeleton and cortactin.

Although the actin cytoskeleton has been implicated in the control of NADPH oxidase in phagocytosis, very little is known about the cytoskeletal regulation of endothelial NADPH oxidase assembly and activation. Here, we report a role for cortactin and the tyrosine phosphorylation of cortactin in hyperoxia-induced NADPH oxidase activation and ROS production in human pulmonary artery ECs (HPAECs). Exposure of HPAECs to hyperoxia for 3 h induced NADPH oxidase activation, as demonstrated by enhanced superoxide production. Hyperoxia also caused a thickening of the subcortical dense peripheral F-actin band and increased the localization of cortactin in the cortical regions and lamellipodia at cell-cell borders that protruded under neighboring cells. Pretreatment of HPAECs with the actin-stabilizing agent phallacidin attenuated hyperoxia-induced cortical actin thickening and ROS production, whereas cytochalasin D and latrunculin A enhanced basal and hyperoxia-induced ROS formation. In HPAECs, a 3-h hyperoxic exposure enhanced the tyrosine phosphorylation of cortactin and interaction between cortactin and p47(phox), a subcomponent of the EC NADPH oxidase, when compared with normoxic cells. Furthermore, transfection of HPAECs with cortactin small interfering RNA or myristoylated cortactin Src homology domain 3 blocking peptide attenuated ROS production and the hyperoxia-induced translocation of p47(phox) to the cell periphery. Similarly, down-regulation of Src with Src small interfering RNA attenuated the hyperoxia-mediated phosphorylation of cortactin tyrosines and blocked the association of cortactin with actin and p47(phox). In addition, the hyperoxia-induced generation of ROS was significantly lower in ECs expressing a tyrosine-deficient mutant of cortactin than in vector control or wild-type cells. These data demonstrate a novel function for cortactin and actin in hyperoxia-induced activation of NADPH oxidase and ROS generation in human lung endothelial cells.

What is the current and future status of conventional amphotericin B?

Amphotericin B deoxycholate has been the 'gold standard' treatment for invasive fungal infections for over 40 years. Driven to improve on the renal toxicity of amphotericin B deoxycholate, extensive pharmaceutical research has led to the development of several new antifungals including lipid formulations of amphotericin B, broad-spectrum azoles and echinocandins. Compared with amphotericin B deoxycholate, the lipid formulations of amphotericin B (amphotericin B lipid complex, amphotericin B colloidal dispersion and liposomal amphotericin B) share distinct advantages in improved drug safety, in particular reduced incidence and severity of amphotericin B deoxycholate-related nephrotoxicity. However, the lipid formulations of amphotericin B are significantly more expensive than amphotericin B deoxycholate and, as for many of these new antifungals, there are as yet insufficient published studies to guide clinicians. This paper examines aspects of safety, efficacy, and health economic data for the lipid formulations of amphotericin B in particular, in order to provide a rationale to justify substituting amphotericin B deoxycholate with the lipid formulations of amphotericin B.

Pharmacoeconomics of antifungal pharmacotherapy--challenges and future directions.

The frequency and severity of invasive fungal infections have been increasingly recognised and new antifungal therapies have expanded the therapeutic armamentarium available to manage such infections. Antifungal agents comprise a significant portion of antibiotic expenditures at major medical centres, prompting adoption of cost-containment measures and treatment guidelines. This paper reviews available data regarding the costs associated with managing fungal infections, including pharmacoeconomic analyses that have been performed in the setting of documented fungal infections, as well as prophylactic and empiric use of antifungal agents. The challenges of performing such studies are discussed, as well as the limitations of published investigations. Finally, recommendations are made regarding the design and implementation of future pharmacoeconomic analyses that can help establish the true costs of managing invasive fungal infections in at-risk patient populations.

Src-mediated tyrosine phosphorylation of p47phox in hyperoxia-induced activation of NADPH oxidase and generation of reactive oxygen species in lung endothelial cells.

Superoxide (O(2)(-)) production by nonphagocytes, similar to phagocytes, is by activation of the NADPH oxidase multicomponent system. Although activation of neutrophil NADPH oxidase involves extensive serine phosphorylation of p47(phox), the role of tyrosine phosphorylation of p47(phox) in NADPH oxidase-dependent O(2)(-) production is unclear. We have shown recently that hyperoxia-induced NADPH oxidase activation in human pulmonary artery endothelial cells (HPAECs) is regulated by mitogen-activated protein kinase signal transduction. Here we provided evidence on the role of nonreceptor tyrosine kinase, Src, in hyperoxia-induced tyrosine phosphorylation of p47(phox) and NADPH oxidase activation in HPAECs. Exposure of HPAECs to hyperoxia for 1 h resulted in increased O(2)(-) and reactive oxygen species (ROS) production and enhanced tyrosine phosphorylation of Src as determined by Western blotting with phospho-Src antibodies. Pretreatment of HPAECs with the Src kinase inhibitor PP2 (1 mum) or transient expression of a dominant-negative mutant of Src attenuated hyperoxia-induced tyrosine phosphorylation of Src and ROS production. Furthermore, exposure of cells to hyperoxia enhanced tyrosine phosphorylation of p47(phox) and its translocation to cell peripheries that were attenuated by PP2. In vitro, Src phosphorylated recombinant p47(phox) in a time-dependent manner. Src immunoprecipitates of cell lysates from control cells revealed the presence of immunodetectable p47(phox) and p67(phox), suggesting the association of oxidase components with Src under basal conditions. Moreover, exposure of HPAECs to hyperoxia for 1 h enhanced the association of p47(phox), but not p67(phox), with Src. These results indicated that Src-dependent tyrosine phosphorylation of p47(phox) regulates hyperoxia-induced NADPH oxidase activation and ROS production in HPAECs.