Payment and Coverage Parity for Virtual Care and In-Person Care: How Do We Get There?

Background: A steep increase in the use of delivery of virtual care occurred during the COVID-19 public health emergency (PHE) because of easing up of payment and coverage restrictions. With the end of PHE, there is uncertainty regarding continued coverage and payment parity for the virtual care services. Methods: On November 8, 2022, The Mass General Brigham held the Third Annual Virtual Care Symposium: Demystifying Clinical Appropriateness in Virtual Care and What's Ahead for Pay Parity. Results: In one of the panels, experts from Mayo Clinic led by Dr. Bart Demaerschalk discussed key issues related to "Payment and Coverage Parity for Virtual Care and In-Person Care: How Do We Get There?" The discussions centered around current policies around payment and coverage parity for virtual care, including state licensure laws for virtual care delivery and the current evidence base regarding outcomes, costs, and resource utilization associated with virtual care. The panel discussion ended with highlighting next steps targeting policymakers, payers, and industry groups to help strengthen the case for parity. Conclusions: To ensure the continued viability of virtual care delivery, legislators and insurers must address the coverage and payment parity between telehealth and in-person visits. This will require a renewed focus on research on clinical appropriateness, parity, equity and access, and economics of virtual care.

Early Serial Echocardiographic and Ultrasonographic Findings in Critically Ill Patients With COVID-19

Background Cardiac function of critically ill patients with COVID-19 generally has been reported from clinically obtained data. Echocardiographic deformation imaging can identify ventricular dysfunction missed by traditional echocardiographic assessment. Research Question What is the prevalence of ventricular dysfunction and what are its implications for the natural history of critical COVID-19? Study Design and Methods This is a multicenter prospective cohort of critically ill patients with COVID-19. We performed serial echocardiography and lower extremity vascular ultrasound on hospitalization days 1, 3, and 8. We defined left ventricular (LV) dysfunction as the absolute value of longitudinal strain of < 17% or LV ejection fraction (LVEF) of < 50%. Primary clinical outcome was inpatient survival. Results We enrolled 110 patients. Thirty-nine (35.5%) died before hospital discharge. LV dysfunction was present at admission in 38 patients (34.5%) and in 21 patients (36.2%) on day 8 (P = .59). Median baseline LVEF was 62% (interquartile range [IQR], 52%-69%), whereas median absolute value of baseline LV strain was 16% (IQR, 14%-19%). Survivors and nonsurvivors did not differ statistically significantly with respect to day 1 LV strain (17.9% vs 14.4%;P = .12) or day 1 LVEF (60.5% vs 65%;P = .06). Nonsurvivors showed worse day 1 right ventricle (RV) strain than survivors (16.3% vs 21.2%;P = .04). Interpretation Among patients with critical COVID-19, LV and RV dysfunction is common, frequently identified only through deformation imaging, and early (day 1) RV dysfunction may be associated with clinical outcome.

Natural selection differences detected in key protein domains between non-pathogenic and pathogenic feline coronavirus phenotypes.

Feline coronaviruses (FCoVs) commonly cause mild enteric infections in felines worldwide (termed feline enteric coronavirus [FECV]), with around 12 per cent developing into deadly feline infectious peritonitis (FIP; feline infectious peritonitis virus [FIPV]). Genomic differences between FECV and FIPV have been reported, yet the putative genotypic basis of the highly pathogenic phenotype remains unclear. Here, we used state-of-the-art molecular evolutionary genetic statistical techniques to identify and compare differences in natural selection pressure between FECV and FIPV sequences, as well as to identify FIPV- and FECV-specific signals of positive selection. We analyzed full-length FCoV protein coding genes thought to contain mutations associated with FIPV (Spike, ORF3abc, and ORF7ab). We identified two sites exhibiting differences in natural selection pressure between FECV and FIPV: one within the S1/S2 furin cleavage site (FCS) and the other within the fusion domain of Spike. We also found fifteen sites subject to positive selection associated with FIPV within Spike, eleven of which have not previously been suggested as possibly relevant to FIP development. These sites fall within Spike protein subdomains that participate in host cell receptor interaction, immune evasion, tropism shifts, host cellular entry, and viral escape. There were fourteen sites (twelve novel sites) within Spike under positive selection associated with the FECV phenotype, almost exclusively within the S1/S2 FCS and adjacent to C domain, along with a signal of relaxed selection in FIPV relative to FECV, suggesting that furin cleavage functionality may not be needed for FIPV. Positive selection inferred in ORF7b was associated with the FECV phenotype and included twenty-four positively selected sites, while ORF7b had signals of relaxed selection in FIPV. We found evidence of positive selection in ORF3c in FCoV-wide analyses, but no specific association with the FIPV or FECV phenotype. We hypothesize that some combination of mutations in FECV may contribute to FIP development, and that it is unlikely to be one singular 'switch' mutational event. This work expands our understanding of the complexities of FIP development and provides insights into how evolutionary forces may alter pathogenesis in coronavirus genomes.

Using Video Modeling to Increase Face-Covering Behavior for Individuals with Down Syndrome in the School Setting

The COVID-19 pandemic has altered the school environment for millions of students worldwide, which has resulted in the need to learn new behaviors, such as wearing face coverings. Teaching students with Down syndrome (DS) new COVID-19 prevention behaviors is essential. Individuals with DS are more likely to contract COVID-19, be hospitalized, and are ten times more likely to die from the disease than individuals without DS (Clift, Coupland, Keogh, Hemingway, & Hippisley-Cox, 2020;Malle et al., 2021). With the need to return students to in-person learning, educators have to quickly identify empirically based teaching tools to teach DS students to wear face coverings. Video modeling (VM) may be one tool that could efficiently teach students with DS to wear face coverings (Park et al., 2019). An intervention package, including VM, was evaluated within a non-concurrent multiple baseline across participants for increasing the time in which 3 participants with DS wore a face covering in the classroom. Results demonstrated that VM alone was an effective antecedent strategy to increase the duration of wearing a face covering for two students. The third participant required behavior specific praise targeting wearing a face covering in addition to VM.

Assessment of burnout and pandemic fatigue among pharmacy leadership in the Veterans Health Administration healthcare system.

DISCLAIMER: In an effort to expedite the publication of articles related to the COVID-19 pandemic, AJHP is posting these manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time. PURPOSE: Factors associated with burnout in Veterans Health Administration (VHA) pharmacy leadership positions were examined during the coronavirus disease 2019 (COVID-19) pandemic. METHODS: A questionnaire was distributed to all pharmacy executives of the VHA healthcare system. It collected demographic and employment characteristics, career satisfaction and work-related variables, indicators of burnout using validated single-item measures adapted from the Maslach Burnout Inventory, and the impact of the COVID-19 pandemic on psychosocial and work-related variables. A χ  2 test with Bonferroni correction was used to evaluate the data. Burnout was defined as a score of 4 or greater on either of the 2 single-item validated statements adapted from the Maslach Burnout Inventory to assess emotional exhaustion and depersonalization. RESULTS: In total, 407 (of 1,027; 39.6%) VHA pharmacy leaders representing Veterans Integrated Service Network pharmacy executives, chiefs of pharmacy, associate chiefs of pharmacy, and inpatient and outpatient supervisors completed the survey. The overall prevalence of burnout was 68.6% using the aggregate measure of emotional exhaustion or depersonalization. Pharmacy leaders who worked more than 60 hours a week reported significantly greater rates of burnout than those who worked 40 to 60 hours a week (86.7% vs 66.9%, χ  2 = 7.34, degrees of freedom = 1, P < 0.05). Those experiencing increased workload related to COVID-19 also reported high burnout rates (72.1%, χ  2 = 16.40, degrees of freedom = 1, P < 0.001). Burnout scores were similar across groups when respondents were stratified by leadership position, gender, age, or years in position. CONCLUSION: As of March 2021, two-thirds of pharmacy leaders were experiencing burnout. It is important for healthcare system leadership to identify patterns of burnout among their pharmacy leaders to ensure a productive and sustainable workforce.

Clostridioides difficile infection in hospitalized pediatric patients: Comparisons of epidemiology, testing, and treatment from 2013 to 2019.

OBJECTIVES: To compare the incidence, epidemiology, testing patterns, treatment, and outcomes of Clostridioides difficile infection (CDI) among hospitalized pediatric patients from 2013 to 2019. STUDY DESIGN: The Pediatric Health Information System database was queried for patient admissions (age 0-17 years) with International Classification of Diseases, 9th and 10th edition, codes for diagnoses of CDI with a billing code for a CDI-related antibiotic treatment. RESULTS: We identified 17 142 pediatric patients, representing 23 052 admissions, with CDI. The adjusted annual CDI incidence decreased over the study period from 7.09 cases per 10 000 patient-days (95% CI, 6.15-8.18) in 2013 to 4.89 cases per 10 000 patient-days (95% CI, 4.03-5.93) in 2019 (P < .001). C difficile-specific testing also decreased during the study period (P < .001). Chronic gastrointestinal conditions (36%) and malignancy (32%) were the most common comorbidities in CDI encounters. Oral metronidazole use decreased during the study period (P < .01) and oral vancomycin use increased (P < .001). CONCLUSIONS: Our study demonstrates a decrease in CDI incidence in hospitalized pediatric patients, a notable change from prior studies, although this may have been influenced by altered testing patterns. We found a high incidence of CDI in patients with cancer and gastrointestinal conditions: groups that warrant targeted evaluation of CDI prevention and treatment.

Development and implementation of a nurse-based remote patient monitoring program for ambulatory disease management.

Introduction: Numerous factors are intersecting in healthcare resulting in an increased focus on new tools and methods for managing care in patients' homes. Remote patient monitoring (RPM) is an option to provide care at home and maintain a connection between patients and providers to address ongoing medical issues. Methods: Mayo Clinic developed a nurse-led RPM program for disease and post-procedural management to improve patient experience, clinical outcomes, and reduce health care utilization by more directly engaging patients in their health care. Enrolled patients are sent a technology package that includes a digital tablet and peripheral devices for the collection of symptoms and vital signs. The data are transmitted from to a hub integrated within the electronic health record. Care team members coordinate patient needs, respond to vital sign alerts, and utilize the data to inform and provide individualized patient assessment, patient education, medication management, goal setting, and clinical care planning. Results: Since its inception, the RPM program has supported nearly 22,000 patients across 17 programs. Patients who engaged in the COVID-19 RPM program experienced a significantly lower rate of 30-day, all-cause hospitalization (13.7% vs. 18.0%, P = 0.01), prolonged hospitalization >7 days (3.5% vs. 6.7%, P = 0.001), intensive care unit (ICU) admission (2.3% vs. 4.2%, P = 0.01), and mortality (0.5% vs. 1.7%, P = 0.01) when compared with those enrolled and unengaged with the technology. Patients with chronic conditions who were monitored with RPM upon hospital discharge were significantly less likely to experience 30-day readmissions (18.2% vs. 23.7%, P = 0.03) compared with those unmonitored. Ninety-five percent of patients strongly agreed or agreed they were likely to recommend RPM to a friend or family member. Conclusions: The Mayo Clinic RPM program has generated positive clinical outcomes and is satisfying for patients. As technology advances, there are greater opportunities to enhance this clinical care model and it should be extended and expanded to support patients across a broader spectrum of needs. This report can serve as a framework for health care organizations to implement and enhance their RPM programs in addition to identifying areas for further evolution and exploration in developing RPM programs of the future.

RASCL: Rapid Assessment of Selection in CLades through molecular sequence analysis.

An important unmet need revealed by the COVID-19 pandemic is the near-real-time identification of potentially fitness-altering mutations within rapidly growing SARS-CoV-2 lineages. Although powerful molecular sequence analysis methods are available to detect and characterize patterns of natural selection within modestly sized gene-sequence datasets, the computational complexity of these methods and their sensitivity to sequencing errors render them effectively inapplicable in large-scale genomic surveillance contexts. Motivated by the need to analyze new lineage evolution in near-real time using large numbers of genomes, we developed the Rapid Assessment of Selection within CLades (RASCL) pipeline. RASCL applies state of the art phylogenetic comparative methods to evaluate selective processes acting at individual codon sites and across whole genes. RASCL is scalable and produces automatically updated regular lineage-specific selection analysis reports: even for lineages that include tens or hundreds of thousands of sampled genome sequences. Key to this performance is (i) generation of automatically subsampled high quality datasets of gene/ORF sequences drawn from a selected "query" viral lineage; (ii) contextualization of these query sequences in codon alignments that include high-quality "background" sequences representative of global SARS-CoV-2 diversity; and (iii) the extensive parallelization of a suite of computationally intensive selection analysis tests. Within hours of being deployed to analyze a novel rapidly growing lineage of interest, RASCL will begin yielding JavaScript Object Notation (JSON)-formatted reports that can be either imported into third-party analysis software or explored in standard web-browsers using the premade RASCL interactive data visualization dashboard. By enabling the rapid detection of genome sites evolving under different selective regimes, RASCL is well-suited for near-real-time monitoring of the population-level selective processes that will likely underlie the emergence of future variants of concern in measurably evolving pathogens with extensive genomic surveillance.

Evolutionary trajectory of receptor binding specificity and promiscuity of the spike protein of SARS-CoV-2.

SARS-CoV-2 infects cells by attachment to its receptor-the angiotensin converting enzyme 2 (ACE2). Regardless of the wealth of structural data, little is known about the physicochemical mechanism of interactions of the viral spike (S) protein with ACE2 and how this mechanism has evolved during the pandemic. Here, we applied experimental and computational approaches to characterize the molecular interaction of S proteins from SARS-CoV-2 variants of concern (VOC). Data on kinetics, activation-, and equilibrium thermodynamics of binding of the receptor binding domain (RBD) from VOC with ACE2 as well as data from computational protein electrostatics revealed a profound remodeling of the physicochemical characteristics of the interaction during the evolution. Thus, as compared to RBDs from Wuhan strain and other VOC, Omicron RBD presented as a unique protein in terms of conformational dynamics and types of non-covalent forces driving the complex formation with ACE2. Viral evolution resulted in a restriction of the RBD structural dynamics, and a shift to a major role of polar forces for ACE2 binding. Further, we investigated how the reshaping of the physicochemical characteristics of interaction affects the binding specificity of S proteins. Data from various binding assays revealed that SARS-CoV-2 Wuhan and Omicron RBDs manifest capacity for promiscuous recognition of unrelated human proteins, but they harbor distinct reactivity patterns. These findings might contribute for mechanistic understanding of the viral tropism and capacity to evade immune responses during evolution.

How to implement paid family and medical leave: A toolkit for practices.

Paid family and medical leave policies are increasingly popular in today's competitive labor market and provide well-documented advantages to all stakeholders. Implementing paid leave for radiologists can seem daunting due to overlapping legal and institutional policies, logistical challenges and call coverage, as well as industry-specific special considerations such as resident education and historical workplace attitudes. This toolkit can empower radiology leaders to implement written paid leave policies in their home institutions and demonstrate that equitable, compassionate institutional policies for paid leave are financially favorable, widely desirable, and increasingly achievable with the right tools in hand.

Impact of COVID-19 on initial emergency medical services certification in the United States.

Objective: As the COVID-19 pandemic began, there were significant concerns for the strength and stability of the emergency medical services (EMS) workforce. These concerns were heightened with the closure of examination centers and the cessation of certification examinations. The impact of this interruption on the EMS workforce is unclear. Our objective was to evaluate the impact of COVID-19 on initial EMS certification in the United States. In addition, we evaluated mitigation measures taken to address these interruptions. Methods: This study was a cross-sectional evaluation of the National Certification Cognitive Examination administration and results for emergency medical technician (EMT) and paramedic candidates. We compared the number of examinations administered and first-attempt pass rates in 2020 (pandemic) to 2019 (control). Descriptive statistics and 2 one-sided tests of equivalence were used to assess if there was a relevant difference of ±5 percentage points. Results: Total number of examinations administered decreased by 15% (EMT, 14%; paramedic, 7%). Without the addition of EMT remote proctoring, the EMT reduction would have been 35%. First-time pass rates were similar in both EMT (-0.9%) and paramedic (-1.9%) candidates, which did not meet our threshold of a relevant difference. Conclusion: COVID-19 has had a measurable impact on examination administration for both levels of certification. First-time pass rates remained unaffected. EMT remote proctoring mitigated some of the impact of COVID-19 on examination administration, although a comparison with mitigation was not assessed. These reductions indicate a potential decrease in the newly certified workforce, but future evaluations will be necessary to assess the presence and magnitude of this impact.

Assessment of Clinician Diagnostic Concordance With Video Telemedicine in the Integrated Multispecialty Practice at Mayo Clinic During the Beginning of COVID-19 Pandemic From March to June 2020.

Importance: There was a shift in patient volume from in-person to video telemedicine visits during the COVID-19 pandemic. Objective: To determine the concordance of provisional diagnoses established at a video telemedicine visit with diagnoses established at an in-person visit for patients presenting with a new clinical problem. Design, Setting, and Participants: This is a diagnostic study of patients who underwent a video telemedicine consultation followed by an in-person outpatient visit for the same clinical problem in the same specialty within a 90-day window. The provisional diagnosis made during the video telemedicine visit was compared with the reference standard diagnosis by 2 blinded, independent medical reviewers. A multivariate logistic regression model was used to determine factors significantly related to diagnostic concordance. The study was conducted at a large academic integrated multispecialty health care institution (Mayo Clinic locations in Rochester, Minnesota; Scottsdale and Phoenix, Arizona; and Jacksonville, Florida; and Mayo Clinic Health System locations in Iowa, Wisconsin, and Minnesota) between March 24 and June 24, 2020. Participants included Mayo Clinic patients residing in the US without age restriction. Data analysis was performed from December 2020 to June 2021. Exposures: New clinical problem assessed via video telemedicine visit to home using Zoom Care Anyplace integrated into Epic. Main Outcomes and Measures: Concordance of provisional diagnoses established over video telemedicine visits compared against a reference standard diagnosis. Results: There were 2393 participants in the analysis. The median (IQR) age of patients was 53 (37-64) years; 1381 (57.7%) identified as female, and 1012 (42.3%) identified as male. Overall, the provisional diagnosis established over video telemedicine visit was concordant with the in-person reference standard diagnosis in 2080 of 2393 cases (86.9%; 95% CI, 85.6%-88.3%). Diagnostic concordance by International Statistical Classification of Diseases and Related Health Problems, Tenth Revision chapter ranged from 64.7% (95% CI, 42.0%-87.4%) for diseases of the ear and mastoid process to 96.8% (95% CI, 94.7%-98.8%) for neoplasms. Diagnostic concordance by medical specialty ranged from 77.3% (95% CI, 64.9%-89.7%) for otorhinolaryngology to 96.0% (92.1%-99.8%) for psychiatry. Specialty care was found to be significantly more likely than primary care to result in video telemedicine diagnoses concordant with a subsequent in-person visit (odds ratio, 1.69; 95% CI, 1.24-2.30; P < .001). Conclusions and Relevance: This diagnostic study of video telemedicine visits yielded a high degree of diagnostic concordance compared with in-person visits for most new clinical concerns. Some specific clinical circumstances over video telemedicine were associated with a lower diagnostic concordance, and these patients may benefit from timely in-person follow-up.

Impact of a High-Risk, Ambulatory COVID-19 Remote Patient Monitoring Program on Utilization, Cost, and Mortality.

OBJECTIVE: To evaluate care utilization, cost, and mortality among high-risk patients enrolled in a coronavirus disease 2019 (COVID-19) remote patient monitoring (RPM) program. METHODS: This retrospective analysis included patients diagnosed with COVID-19 at risk for severe disease who enrolled in the RPM program between March 2020 and October 2021. The program included in-home technology for symptom and physiologic data monitoring with centralized care management. Propensity score matching established matched cohorts of RPM-engaged (defined as ≥1 RPM technology interactions) and non-engaged patients using a logistic regression model of 59 baseline characteristics. Billing codes and the electronic death certificate system were used for data abstraction from the electronic health record and reporting of care utilization and mortality endpoints. RESULTS: Among 5796 RPM-enrolled patients, 80.0% engaged with the technology. Following matching, 1128 pairs of RPM-engaged and non-engaged patients comprised the analysis cohorts. Mean patient age was 63.3 years, 50.9% of patients were female, and 81.9% were non-Hispanic White. Patients who were RPM-engaged experienced significantly lower rates of 30-day, all-cause hospitalization (13.7% vs 18.0%, P=.01), prolonged hospitalization (3.5% vs 6.7%, P=.001), intensive care unit admission (2.3% vs 4.2%, P=.01), and mortality (0.5% vs 1.7%; odds ratio, 0.31; 95% CI, 0.12 to 0.78; P=.01), as well as cost of care ($2306.33 USD vs $3565.97 USD, P=0.04), than those enrolled in RPM but non-engaged. CONCLUSION: High-risk COVID-19 patients enrolled and engaged in an RPM program experienced lower rates of hospitalization, intensive care unit admission, mortality, and cost than those enrolled and non-engaged. These findings translate to improved hospital bed access and patient outcomes.

Conserved recombination patterns across coronavirus subgenera.

Recombination contributes to the genetic diversity found in coronaviruses and is known to be a prominent mechanism whereby they evolve. It is apparent, both from controlled experiments and in genome sequences sampled from nature, that patterns of recombination in coronaviruses are non-random and that this is likely attributable to a combination of sequence features that favour the occurrence of recombination break points at specific genomic sites, and selection disfavouring the survival of recombinants within which favourable intra-genome interactions have been disrupted. Here we leverage available whole-genome sequence data for six coronavirus subgenera to identify specific patterns of recombination that are conserved between multiple subgenera and then identify the likely factors that underlie these conserved patterns. Specifically, we confirm the non-randomness of recombination break points across all six tested coronavirus subgenera, locate conserved recombination hot- and cold-spots, and determine that the locations of transcriptional regulatory sequences are likely major determinants of conserved recombination break-point hotspot locations. We find that while the locations of recombination break points are not uniformly associated with degrees of nucleotide sequence conservation, they display significant tendencies in multiple coronavirus subgenera to occur in low guanine-cytosine content genome regions, in non-coding regions, at the edges of genes, and at sites within the Spike gene that are predicted to be minimally disruptive of Spike protein folding. While it is apparent that sequence features such as transcriptional regulatory sequences are likely major determinants of where the template-switching events that yield recombination break points most commonly occur, it is evident that selection against misfolded recombinant proteins also strongly impacts observable recombination break-point distributions in coronavirus genomes sampled from nature.

A Scalable Framework for Telehealth: The Mayo Clinic Center for Connected Care Response to the COVID-19 Pandemic.

Background: The Mayo Clinic Center for Connected Care has an established organizational framework for telehealth care delivery. It provides patients, consumers, care teams, and referring providers access to clinical knowledge through technologies and integrated practice models. Central to the framework are teams that support product management and operational functions. They work together across the asynchronous, synchronous video telemedicine, remote patient monitoring (RPM), and mobile core service lines. Methods: The organizational framework of the Center for Connected Care and Mayo Clinic telehealth response to the COVID-19 pandemic is described. Barriers to telehealth delivery that were addressed by the public health emergency are also reported. This report was deemed exempt from full review by the Mayo Clinic IRB. Results: After declaration of the COVID-19 pandemic, there was rapid growth in established telehealth offerings, including patient online services account creation, secure messaging, inpatient eConsults, express care online utilization, and video visits to home. Census for the RPM program for patients with chronic conditions remained stable; however, its framework was rapidly adapted to develop and implement a COVID-19 RPM service. In addition to this, other new telehealth and virtual care services were created to support the unique needs of patients with COVID-19 symptoms or disease and the health care workforce, including a digital COVID-19 self-assessment tool and video telemedicine solutions for ambulances, emergency departments, intensive care units, and designated medical-surgical units. Conclusion: Rapid growth, adoption, and sustainability of telehealth services through the COVID-19 pandemic were made possible by a scalable framework for telehealth and alignment of regulatory and reimbursement models.

Potent human broadly SARS-CoV-2-neutralizing IgA and IgG antibodies effective against Omicron BA.1 and BA.2.

Memory B-cell and antibody responses to the SARS-CoV-2 spike protein contribute to long-term immune protection against severe COVID-19, which can also be prevented by antibody-based interventions. Here, wide SARS-CoV-2 immunoprofiling in Wuhan COVID-19 convalescents combining serological, cellular, and monoclonal antibody explorations revealed humoral immunity coordination. Detailed characterization of a hundred SARS-CoV-2 spike memory B-cell monoclonal antibodies uncovered diversity in their repertoire and antiviral functions. The latter were influenced by the targeted spike region with strong Fc-dependent effectors to the S2 subunit and potent neutralizers to the receptor-binding domain. Amongst those, Cv2.1169 and Cv2.3194 antibodies cross-neutralized SARS-CoV-2 variants of concern, including Omicron BA.1 and BA.2. Cv2.1169, isolated from a mucosa-derived IgA memory B cell demonstrated potency boost as IgA dimers and therapeutic efficacy as IgG antibodies in animal models. Structural data provided mechanistic clues to Cv2.1169 potency and breadth. Thus, potent broadly neutralizing IgA antibodies elicited in mucosal tissues can stem SARS-CoV-2 infection, and Cv2.1169 and Cv2.3194 are prime candidates for COVID-19 prevention and treatment.

Evolutionary trajectory of the physicochemical mechanism of interaction of SARS-CoV-2 spike protein with ACE2 (preprint)

SARS-CoV-2 infects cells by attachment to its receptor the angiotensin converting enzyme 2 (ACE2). Regardless of the wealth of structural data, little is known about the physicochemical mechanism of interactions of the viral spike (S) protein with ACE2 and how this mechanism has evolved during the pandemic. Here, we applied experimental and computational approaches to characterize the molecular interaction of S proteins from SARS-CoV-2 variants of concern (VOC). Data on kinetics, activation- and equilibrium thermodynamics of binding of the receptor binding domain (RBD) from VOC with ACE2 as well as data from computational protein electrostatics revealed a profound remodeling of the physicochemical characteristics of the interaction during the evolution. Thus, as compared to RBDs from Wuhan strain and other VOC, Omicron RBD presented as a unique protein in terms of conformational dynamics and types of non-covalent forces driving the complex formation with ACE2. Viral evolution resulted in a restriction of the RBD structural dynamics, and a shift to a major role of electrostatic forces for ACE2 binding. Further, we investigated how the reshaping of the physicochemical qualities affect the functional properties of S proteins. Data from various binding assays revealed that SARS-CoV-2 Wuhan and Omicron RBDs manifest capacity for off-target (promiscuous) recognition of multiple unrelated proteins, but they harbor distinct reactivity patterns. This study provides mechanistic explanations for changes in the viral tropism, infectivity, and capacity to evade immune responses during evolution.

Recent Zoonotic Spillover and Tropism Shift of a Canine Coronavirus Is Associated with Relaxed Selection and Putative Loss of Function in NTD Subdomain of Spike Protein.

A canine coronavirus (CCoV) has now been reported from two independent human samples from Malaysia (respiratory, collected in 2017-2018; CCoV-HuPn-2018) and Haiti (urine, collected in 2017); these two viruses were nearly genetically identical. In an effort to identify any novel adaptations associated with this apparent shift in tropism we carried out detailed evolutionary analyses of the spike gene of this virus in the context of related Alphacoronavirus 1 species. The spike 0-domain retains homology to CCoV2b (enteric infections) and Transmissible Gastroenteritis Virus (TGEV; enteric and respiratory). This domain is subject to relaxed selection pressure and an increased rate of molecular evolution. It contains unique amino acid substitutions, including within a region important for sialic acid binding and pathogenesis in TGEV. Overall, the spike gene is extensively recombinant, with a feline coronavirus type II strain serving a prominent role in the recombinant history of the virus. Molecular divergence time for a segment of the gene where temporal signal could be determined, was estimated at around 60 years ago. We hypothesize that the virus had an enteric origin, but that it may be losing that particular tropism, possibly because of mutations in the sialic acid binding region of the spike 0-domain.

Permissive Omicron breakthrough infections in individuals with binding or neutralizing antibodies to ancestral SARS-CoV-2 (preprint)

Background Breakthrough infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant (B.1.1.529) has occurred in populations with high vaccination rates. These infections are due to sequence variation in the spike protein leading to a reduction in protection afforded by the current vaccines, which are based on the original Wuhan-Hu-1 strain, or by natural infection with pre-Omicron strains. Methods In a longitudinal cohort study, pre-breakthrough infection sera for Omicron breakthroughs (n=12) were analyzed. Assays utilized include a laboratory-developed solid phase binding assay to recombinant spike protein, a commercial assay to the S1 domain of the spike protein calibrated to the World Health Organization (WHO) standard, and a commercial solid-phase surrogate neutralizing activity (SNA) assay. All assays employed spike protein preparations based on sequences from the Wuhan-Hu-1 strain. Participant demographics and clinical characteristics were captured. Results Pre-breakthrough binding antibody (bAB) titers ranged from 1:800-1:51,200 for the laboratory-developed binding assay, which correlated well and agreed quantitatively with the commercial spike S1 domain WHO calibrated assay. SNA was detected in 10/12 (83%) samples. Conclusions Neither high bAB nor SNA were markers of protection from Omicron infection/re-infection. Laboratory tests with antigen targets based on Wuhan-Hu-1 may not accurately reflect the degree of immune protection from variants with significant spike protein differences. Omicron breakthrough infections are likely due to high sequence variation of the spike protein and reflect incomplete immune protection from previous infection with strains that preceded Omicron or with vaccinations based on the original Wuhan-Hu-1 strain.

The COVID-19 vaccine concerns scale: Development and validation of a new measure.

Reasons for COVID-19 hesitancy are multi-faceted and tend to differ from those for general vaccine hesitancy. We developed the COVID-19 Vaccine Concerns Scale (CVCS), a self-report measure intended to better understand individuals' concerns about COVID-19 vaccines. We validated the scale using data from a convenience sample of 2,281 emergency medical services providers, a group of professionals with high occupational COVID-19 risk. Measures included the CVCS items, an adapted Oxford COVID-19 vaccine hesitancy scale, a general vaccine hesitancy scale, demographics, and self-reported COVID-19 vaccination status. The CVCS had high internal consistency reliability (α = .89). A one-factor structure was determined by exploratory and confirmatory factor analyses (EFA and CFA), resulting in a seven-item scale. The model had good fit (X2[14] = 189.26, p < .001; CFI = .95, RMSEA = .11 [.09, .12], NNFI = .93, SRMR = .03). Moderate Pearson correlations with validated scales of general vaccine hesitancy (r = .71 , p < .001; n = 2144) and COVID-19 vaccine hesitancy (r = .82; p < .001; n = 2279) indicated construct validity. The CVCS predicted COVID-19 vaccination status (B = -2.21, Exp(B) = .11 [95% CI = .09, .13], Nagelkerke R2 = .55), indicating criterion-related validity. In sum, the 7-item CVCS is a reliable and valid self-report measure to examine fears and concerns about COVID-19 vaccines. The scale predicts COVID-19 vaccination status and can be used to inform efforts to reduce COVID-19 vaccine hesitancy.