Comparing antibody assays as correlates of protection against COVID-19 in the COVE mRNA-1273 vaccine efficacy trial.

The best assay or marker to define mRNA-1273 vaccine-induced antibodies as a correlate of protection (CoP) is unclear. In the COVE trial, participants received two doses of the mRNA-1273 COVID-19 vaccine or placebo. We previously assessed IgG binding antibodies to the spike protein (spike IgG) or receptor binding domain (RBD IgG) and pseudovirus neutralizing antibody 50 or 80% inhibitory dilution titer measured on day 29 or day 57, as correlates of risk (CoRs) and CoPs against symptomatic COVID-19 over 4 months after dose. Here, we assessed a new marker, live virus 50% microneutralization titer (LV-MN50), and compared and combined markers in multivariable analyses. LV-MN50 was an inverse CoR, with a hazard ratio of 0.39 (95% confidence interval, 0.19 to 0.83) at day 29 and 0.51 (95% confidence interval, 0.25 to 1.04) at day 57 per 10-fold increase. In multivariable analyses, pseudovirus neutralization titers and anti-spike binding antibodies performed best as CoRs; combining antibody markers did not improve correlates. Pseudovirus neutralization titer was the strongest independent correlate in a multivariable model. Overall, these results supported pseudovirus neutralizing and binding antibody assays as CoRs and CoPs, with the live virus assay as a weaker correlate in this sample set. Day 29 markers performed as well as day 57 markers as CoPs, which could accelerate immunogenicity and immunobridging studies.

Chikungunya virus infection in Cynomolgus macaques following Intradermal and aerosol exposure.

BACKGROUND: Chikungunya virus (CHIKV) is transmitted via mosquito bite and potentially by aerosol, causing chikungunya fever and arthritic disease in humans. There are currently no licensed vaccines or antiviral therapeutics to protect against CHIKV infection in humans. Animal models recapitulating human disease, especially for transmission by aerosol, are needed for licensure of such medical countermeasures. METHODS: Cynomolgus macaques (CMs) were challenged by intradermal (ID) inoculation or exposure to an aerosol containing CHIKV Ross strain at different target infectious doses (103-107 plaque forming units (PFU)). The clinical and virologic courses of disease were monitored up to 14 days post-exposure. RESULTS: ID infection of CMs led to overt clinical disease, detectable viremia, and increased blood markers of liver damage. Animals challenged by aerosol exhibited viremia and increased liver damage biomarkers with minimal observed clinical disease. All animals survived CHIKV challenge. CONCLUSIONS: We have described CHIKV infection in CMs following ID inoculation and, for the first time, infection by aerosol. Based on limited reported cases in the published literature, the aerosol model recapitulates the virologic findings of human infection via this route. The results of this study provide additional evidence for the potential use of CMs as a model for evaluating medical countermeasures against CHIKV.

Ectromelia Virus Disease Characterization in the BALB/c Mouse: A Surrogate Model for Assessment of Smallpox Medical Countermeasures.

In 2007, the United States- Food and Drug Administration (FDA) issued guidance concerning animal models for testing the efficacy of medical countermeasures against variola virus (VARV), the etiologic agent for smallpox. Ectromelia virus (ECTV) is naturally-occurring and responsible for severe mortality and morbidity as a result of mousepox disease in the murine model, displaying similarities to variola infection in humans. Due to the increased need of acceptable surrogate animal models for poxvirus disease, we have characterized ECTV infection in the BALB/c mouse. Mice were inoculated intranasally with a high lethal dose (125 PFU) of ECTV, resulting in complete mortality 10 days after infection. Decreases in weight and temperature from baseline were observed eight to nine days following infection. Viral titers via quantitative polymerase chain reaction (qPCR) and plaque assay were first observed in the blood at 4.5 days post-infection and in tissue (spleen and liver) at 3.5 days post-infection. Adverse clinical signs of disease were first observed four and five days post-infection, with severe signs occurring on day 7. Pathological changes consistent with ECTV infection were first observed five days after infection. Examination of data obtained from these parameters suggests the ECTV BALB/c model is suitable for potential use in medical countermeasures (MCMs) development and efficacy testing.

Functional improvement after humeral shaft nonunion in a patient with glenohumeral ankylosis.

Functionally limiting heterotopic ossification about the shoulder represents an uncommon clinical entity, which has been most commonly reported as a consequence of prolonged immobilization in intensive care unit patients. Severe cases may result in complete glenohumeral ankylosis, with resultant upper extremity motion through the scapulothoracic joint, and significant functional consequences. We report the case of a 72-year-old male with spontaneous glenohumeral ankylosis who suffered a humeral shaft fracture with resultant painless nonunion. Motion through the nonunion site caused significant subjective functional improvements, increased range of motion, and the ability to complete his activities of daily living. Patients with limited shoulder range of motion may be at higher risk for humeral fractures and nonunion. These patients, however, may experience improved function due to increased upper extremity range of motion through the nonunion site.

Implantation and monitoring of a novel telemetry unit in the Syrian golden hamster model.

Radiotelemetry allows for real-time remote monitoring of biological parameters in freely moving laboratory animals. The HD-X11 transmitter is a novel telemetry device that enables simultaneous collection of body temperature, activity, blood pressure, electrocardiogram (ECG), and other biopotentials in small animal models. Previously, researchers could only collect either blood pressure or ECG parameters; prioritizing the signal of most interest or increasing the number of animals on study to capture both signals at one time. This new device eliminates the need for separate animal groups for assorted measurements and allows for a more complete cardiovascular assessment. Evaluation of the transmitter from both surgical and data collection perspectives indicates that the HD-X11 transmitter can be a useful tool to researchers in a wide range of scientific and medical fields.

Inhibition of Lassa virus and Ebola virus infection in host cells treated with the kinase inhibitors genistein and tyrphostin.

Arenaviruses and filoviruses are capable of causing hemorrhagic fever syndrome in humans. Limited therapeutic and/or prophylactic options are available for humans suffering from viral hemorrhagic fever. In this report, we demonstrate that pre-treatment of host cells with the kinase inhibitors genistein and tyrphostin AG1478 leads to inhibition of infection or transduction in cells infected with Ebola virus, Marburg virus, and Lassa virus. In all, the results demonstrate that a kinase inhibitor cocktail consisting of genistein and tyrphostin AG1478 is a broad-spectrum antiviral that may be used as a therapeutic or prophylactic against arenavirus and filovirus hemorrhagic fever.

Genistein, a general kinase inhibitor, as a potential antiviral for arenaviral hemorrhagic fever as described in the Pirital virus-Syrian golden hamster model.

Arenaviruses are rodent-borne negative strand RNA viruses and infection of these viruses in humans may result in disease and hemorrhagic fever. To date, supportive care, ribavirin, and in some cases immune plasma remain the foremost treatment options for arenaviral hemorrhagic fever. Research with the hemorrhagic fever causing-arenaviruses usually requires a Biosafety level (BSL)-4 environment; however, surrogate animal model systems have been developed to preliminarily study and screen various vaccines and antivirals. The Syrian golden hamster-Pirital virus (PIRV) surrogate model of hemorrhagic fever provides an opportunity to test new antivirals in an ABSL-3 setting. Thus, we challenged hamsters, implanted with telemetry, with PIRV and observed viremia and tissue viral titers, and changes in core body temperature, hematology, clinical chemistry, and coagulation parameters. Physical signs of disease of the PIRV-infected hamsters included weight loss, lethargy, petechial rashes, epistaxis, ocular orbital and rectal hemorrhage, and visible signs of neurologic disorders. However, treating animals with genistein, a plant derived isoflavone and general kinase inhibitor, resulted in increased survival rates and led to an improved clinical profile. In all, the results from this study demonstrate the potential of a general kinase inhibitor genistein as an antiviral against arenaviral hemorrhagic fever.