A Novel Antigenic Site Spanning Domains I and III of the Zika Virus Envelope Glycoprotein Is the Target of Strongly Neutralizing Human Monoclonal Antibodies.

Zika virus (ZIKV), a mosquito-transmitted flavivirus, caused a large epidemic in Latin America between 2015 and 2017. Effective ZIKV vaccines and treatments are urgently needed to prevent future epidemics and severe disease sequelae. People infected with ZIKV develop strongly neutralizing antibodies linked to viral clearance and durable protective immunity. To understand the mechanisms of protective immunity and to support the development of ZIKV vaccines, we characterize here a strongly neutralizing antibody, B11F, isolated from a patient who recovered from ZIKV. Our results indicate that B11F targets a complex epitope on the virus that spans domains I and III of the envelope glycoprotein. While previous studies point to quaternary epitopes centered on domain II of the ZIKV E glycoprotein as targets of strongly neutralizing and protective human antibodies, we uncover a new site spanning domains I and III as a target of strongly neutralizing human antibodies.IMPORTANCE People infected with Zika virus develop durable neutralizing antibodies that prevent repeat infections. In the current study, we characterize a ZIKV-neutralizing human monoclonal antibody isolated from a patient after recovery. Our studies establish a novel site on the viral envelope that is targeted by human neutralizing antibodies. Our results are relevant to understanding how antibodies block infection and to guiding the design and evaluation of candidate vaccines.

Production of the Receptor-binding Domain of the Viral Spike Proteins from 2003 and 2019 SARS CoVs and the Four Common Human Coronaviruses for Serologic Assays and Inhibitor Screening.

The recombinant receptor-binding domain (RBD) of the viral spike protein from SARS-CoV-1 and 2 are reliable antigens for detecting viral-specific antibodies in humans. We and others have shown that the levels of RBD-binding antibodies and SARS-CoV-2 neutralizing antibodies in patients are correlated. Here, we report the expression and purification of properly folded RBD proteins from SARS and common-cold HCoVs in mammalian cells. RBD proteins were produced with cleavable tags for affinity purification from the cell culture medium and to support multiple immunoassay platforms and drug discovery efforts. Graphic abstract: High-Yield Production of Viral Spike RBDs for Diagnostics and Drug Discovery.

Sex Disparities and Neutralizing-Antibody Durability to SARS-CoV-2 Infection in Convalescent Individuals.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2 months after infection or the reason for the discrepancy in COVID-19 disease and sex. Using convalescent-phase sera collected from 101 COVID-19-recovered individuals 21 to 212 days after symptom onset with 48 additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations of individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to 6 months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex and in individuals with cardiometabolic comorbidities. IMPORTANCE In this study, we found that neutralizing antibody responses in COVID-19-convalescent individuals vary in magnitude but are durable and correlate well with receptor binding domain (RBD) Ig binding antibody levels compared to other SARS-CoV-2 antigen responses. In our cohort, higher neutralizing antibody titers are independently and significantly associated with male sex compared to female sex. We also show for the first time that higher convalescent antibody titers in male donors are associated with increased age and symptom grade. Furthermore, cardiometabolic comorbidities are associated with higher antibody titers independently of sex. Here, we present an in-depth evaluation of serologic, demographic, and clinical correlates of functional antibody responses and durability to SARS-CoV-2 which supports the growing literature on sex discrepancies regarding COVID-19 disease morbidity and mortality, as well as functional neutralizing antibody responses to SARS-CoV-2.

Sex disparities and neutralizing antibody durability to SARS-CoV-2 infection in convalescent individuals.

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2. Using convalescent sera collected from 101 COVID-19 recovered individuals 21-212 days after symptom onset with forty-eight additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations between individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to six months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex. We also show that SARS-CoV-2 convalescent neutralizing antibodies are higher in individuals with cardio-metabolic comorbidities.

Effect of an academic detailing intervention on the utilization rate of cyclooxygenase-2 inhibitors in the elderly.

BACKGROUND: Osteoarthritis is prevalent in the elderly. Nova Scotia general practitioners (GPs) identified the need for an academic detailing (AD) intervention aimed at optimizing the management of osteoarthritis. AD was provided by Dalhousie University Continuing Medical Education in a face-to-face encounter employing evidence-based information. GP participation was voluntary. OBJECTIVE: To evaluate the effect of a GP-targeted osteoarthritis AD intervention on a reduction in the prescribing of cyclooxygenase-2 (COX-2) inhibitors, as well as examine the intervention effect on the utilization rates of gastroprotective agents and medical services. METHODS: A retrospective cohort study design employing administrative data was used. Differences in utilization rates between intervention and control groups were evaluated using generalized estimating equations analysis for longitudinal data over four 90-day postintervention periods. Confounding was addressed using propensity scores to adjust for between-group bias on the measured covariates. RESULTS: The between-group difference for change in COX-2 utilization rates was 0.76 defined daily doses/patient (p = 0.040; 95% CI 0.037 to 1.48) for the 3-month period following the intervention, with lower COX-2 utilization in the AD intervention group than in the control group. The intervention group showed a significant decrease in the within-group utilization rate between the pre- and postintervention periods (z =-2.34; p = 0.019). The between-group difference for change in GP office visit rates was 0.40 visits/patient (p = 0.028; 95% CI 0.046 to 0.79) with the intervention group, showing higher visit rates compared with the control group. CONCLUSIONS: The osteoarthritis AD intervention was associated with a significant decrease (23%) in COX-2 utilization rates in the 3-month period immediately following the intervention. The only secondary outcome to show a significant between-group effect was the GP office visit rate, which was higher for the intervention group in the second 3-month postintervention period.

The relationship between type of drug therapy and blood glucose self-monitoring test strips claimed by beneficiaries of the Seniors' Pharmacare Program in Nova Scotia, Canada.

BACKGROUND: The healthcare expenditure on self-monitoring of blood glucose (SMBG) test strips under the Nova Scotia Seniors' Pharmacare Program (NSSPP) has increased significantly in recent years. The objective of this study was to identify the frequency and cost of claims for blood glucose monitoring test strips by NSSPP beneficiaries in the fiscal year 2005/06 and to explore the variation in the use of test strips by type of treatment, age and sex. METHODS: Retrospective analysis was conducted using pharmacy administrative claims data for NSSPP beneficiaries. Study subjects were aged > or = 65 years on October 1, 2004, received SMBG test strips in the 110 days prior to April 1, 2005, and were alive throughout the twelve month study period. Subjects were categorized into four groups: insulin only, oral antihyperglycemic agents (OAA) only, both OAA and insulin; and no reimbursed diabetes medications. Statistical analysis was performed to identify differences in expenditure by medication group and in frequency of SMBG test strips claimed by medication group, age, and sex. RESULTS: Of 13,564 included beneficiaries, 13.2% were categorized as insulin only, 53.5% OAA only, 7.2% both OAA and insulin, and 26.0% no reimbursed diabetes medications. Over half (58.7%) were femle. The insulin only category had the highest mean (+/- SD) number of SMBG test strips claimed per day (2.0 +/- 1.5) with a mean annual total cost of $615 +/- $441/beneficiary. Beneficiaries aged 80 years and above claimed fewer test strips than beneficiaries below 80 years. CONCLUSION: This population based study shows that in Nova Scotia the SMBG test strips claimed by the majority of seniors were within Canadian guidelines. However, a small proportion of beneficiaries claimed for SMBG test strips infrequently or too frequently, which suggests areas for improvement. The provincial drug plan covers the majority of the costs of test strip utilization, suggesting that the majority of test strips claimed did not exceed the maximum allowable cost (MAC) established in the program's MAC policy. Drug insurance programs need to work with healthcare providers to determine if patients are using test strips optimally; and to determine their impact on patient outcomes. In addition, they need to determine the cost-effectiveness of their SMBG test strip reimbursement policies.