Remdesivir for the Treatment of Covid-19 - Preliminary Report

BACKGROUND: Although several therapeutic agents have been evaluated for the treatment of coronavirus disease 2019 (Covid-19), none have yet been shown to be efficacious. METHODS: We conducted a double-blind, randomized, placebo-controlled trial of intravenous remdesivir in adults hospitalized with Covid-19 with evidence of lower respiratory tract involvement. Patients were randomly assigned to receive either remdesivir (200 mg loading dose on day 1, followed by 100 mg daily for up to 9 additional days) or placebo for up to 10 days. The primary outcome was the time to recovery, defined by either discharge from the hospital or hospitalization for infection-control purposes only. RESULTS: A total of 1063 patients underwent randomization. The data and safety monitoring board recommended early unblinding of the results on the basis of findings from an analysis that showed shortened time to recovery in the remdesivir group. Preliminary results from the 1059 patients (538 assigned to remdesivir and 521 to placebo) with data available after randomization indicated that those who received remdesivir had a median recovery time of 11 days (95% confidence interval [CI], 9 to 12), as compared with 15 days (95% CI, 13 to 19) in those who received placebo (rate ratio for recovery, 1.32; 95% CI, 1.12 to 1.55; P \u3c 0.001). The Kaplan-Meier estimates of mortality by 14 days were 7.1% with remdesivir and 11.9% with placebo (hazard ratio for death, 0.70; 95% CI, 0.47 to 1.04). Serious adverse events were reported for 114 of the 541 patients in the remdesivir group who underwent randomization (21.1%) and 141 of the 522 patients in the placebo group who underwent randomization (27.0%). CONCLUSIONS: Remdesivir was superior to placebo in shortening the time to recovery in adults hospitalized with Covid-19 and evidence of lower respiratory tract infection. (Funded by the National Institute of Allergy and Infectious Diseases and others; ACCT-1 ClinicalTrials.gov number, NCT04280705.)

A Rapid Flp-In System for Expression of Secreted H5N1 Influenza Hemagglutinin Vaccine Immunogen in Mammalian Cells

Continuing transmissions of highly pathogenic H5N1 viruses in poultry and humans underscores the need for a rapid response to potential pandemic in the form of vaccine. Recombinant technologies for production of immunogenic hemagglutinin (HA) could provide an advantage over the traditional inactivated vaccine manufacturing process. Generation of stably transfected mammalian cells secreting properly folded HA proteins is important for scalable controlled manufacturing.We have developed a Flp-In based 293 stable cell lines through targeted site-specific recombination for expression of secreted hemagglutinin (HA) proteins and evaluated their immunogenicity. H5N1 globular domain HA1(1-330) and HA0(1-500) proteins were purified from the supernatants of 293 Flp-In stable cell lines. Both proteins were properly folded as confirmed by binding to H5N1-neutralizing conformation-dependent human monoclonal antibodies. The HA0 (with unmodified cleavage site) was monomeric, while the HA1 contained oligomeric forms. Upon rabbit immunization, both HA proteins elicited neutralizing antibodies against the homologous virus (A/Vietnam/1203/2004, clade 1) as well as cross-neutralizing antibodies against heterologous H5N1 clade 2 strains, including A/Indonesia/5/2005. These results exceeded the human antibody responses against the inactivated sub-virion H5N1 vaccine.Our data suggest that the 293 Flp-In system could serve as a platform for rapid expression of HA immunogens in mammalian cells from emerging influenza strains

Understanding the treatment benefit of hyperimmune anti-influenza intravenous immunoglobulin (Flu-IVIG) for severe human influenza

Background: Antibody-based therapies for respiratory viruses are of increasing importance. The INSIGHT 006 trial administered anti-influenza hyperimmune intravenous immunoglobulin (Flu-IVIG) to patients hospitalized with influenza. Flu-IVIG treatment improved outcomes in patients with influenza B but showed no benefit for influenza A. Methods: To probe potential mechanisms of Flu-IVIG utility, sera collected from patients hospitalized with influenza A or B viruses (IAV or IBV) were analyzed for antibody isotype/subclass and Fcγ receptor (FcγR) binding by ELISA, bead-based multiplex, and NK cell activation assays. Results: Influenza-specific FcγR-binding antibodies were elevated in Flu-IVIG–infused IBV- and IAV-infected patients. In IBV-infected participants (n = 62), increased IgG3 and FcγR binding were associated with more favorable outcomes. Flu-IVIG therapy also improved the odds of a more favorable outcome in patients with low levels of anti-IBV Fc-functional antibody. Higher FcγR-binding antibody was associated with less favorable outcomes in IAV-infected patients (n = 50), and Flu-IVIG worsened the odds of a favorable outcome in participants with low levels of anti-IAV Fc-functional antibody. Conclusion: These detailed serological analyses provide insights into antibody features and mechanisms required for a successful humoral response against influenza, suggesting that IBV-specific, but not IAV-specific, antibodies with Fc-mediated functions may assist in improving influenza outcome. This work will inform development of improved influenza immunotherapies

Penicillium citrinum: Opportunistic pathogen or idle bystander? A case analysis with demonstration of galactomannan cross-reactivity

We present a case of an immunocompromised woman with fever, pulmonary infiltrates and multiple bronchoalveolar lavage (BAL) cultures positive for Penicillium citrinum with a concomitant high BAL galactomannan level. We report the results of Aspergillus galactomannan testing performed on culture supernatants from her P. citrinum strain that confirmed the suspected cross-reactivity. Finally, we discuss the clinical significance and antifungal susceptibility of P. citrinum in our case and review the literature

Epidemiology and clinical characteristics of respiratory syncytial virus infections among children and adults in Mexico

BACKGROUND: Respiratory syncytial virus (RSV) is a leading etiological agent of acute respiratory tract infections and hospitalizations in children. However, little information is available regarding RSV infections in Latin American countries, particularly among adult patients. OBJECTIVE: To describe the epidemiology of RSV infection and to analyze the factors associated with severe infections in children and adults in Mexico. METHODS: Patients ≥1 month old, who presented with an influenza-like illness (ILI) to six hospitals in Mexico, were eligible for participation in the study. Multiplex reverse-transcriptase polymerase chain reaction identified viral pathogens in nasal swabs from 5629 episodes of ILI. Patients in whom RSV was detected were included in this report. RESULTS: Respiratory syncytial virus was detected in 399 children and 171 adults. RSV A was detected in 413 cases and RSV B in 163, including six patients who had coinfection with both subtypes; 414 (72.6%) patients required hospital admission, including 96 (16.8%) patients that required admission to the intensive care unit. Coinfection with one or more respiratory pathogens other than RSV was detected in 159 cases. Young age (in children) and older age (in adults) as well as the presence of some underlying conditions were associated with more severe disease. CONCLUSIONS: This study confirms that RSV is an important respiratory pathogen in children in Mexico. In addition, a substantial number of cases in adults were also detected highlighting the relevance of this virus in all ages. It is important to identify subjects at high risk of complications who may benefit from current or future preventive interventions.La Red is funded by the Mexico Ministry of Health and the U.S. National Institute of Allergy and Infectious Diseases. This project has been funded in part by funding provided by CONACYT (Fondo Sectorial SSA/IMSS/ISSSTE, Projects No. 71260 and No. 127088); National Institute of Allergy and Infectious Diseases, National Institutes of Health, through its Intramural Research Programs and a contract with Westat, Inc., Contract Number: HHSN2722009000031, Task Order Number: HHSN27200002; and through the National Cancer Institute, National Institutes of Health, under Contract No. HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, or Westat, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government.S

Development of neutralizing and anti-HA binding antibodies in rabbits following vaccination with H5N1 HA1 and HA0 proteins produced using Flp-In system.

<p>(A–D) Antibody kinetics following H5N1 HA1 & HA0 vaccination in rabbits. Steady-state binding equilibrium analysis of pre & post-H5N1 HA1 immune sera (rabbit K8) in (A–B) or pre- & post-H5N1 HA0 immune sera (rabbit K9) in (C–D) to Flp-In derived H5N1 HA1 and HA0 proteins were measured using SPR. Ten-fold diluted individual post-vaccinated sera from each time point, were injected simultaneously onto recombinant Flp-In H5N1 HA1 in (A and C) and H5N1 HA0 in (B and D), immobilized on a sensor chip through the free amine group, and onto a blank flow cell, free of peptide. Binding was recorded using ProteOn system surface plasmon resonance biosensor instrument (BioRad Labs, Hercules, CA). (E) Flp-In HA1 and HA0 elicit high cross-neutralizing antibody titers against homologous and heterologous H5N1 viruses. Animals were immunized with 100 mg proteins mixed every three weeks. Sera was collected at 8^th day after each vaccination and analyzed in a microneutralization assay against various H5N1 virus strains. Data is representative of three experiments.</p