covid-19 ASSAYS and studies

– Efficacy assay for antivirals in cell culture (Vero typically)

– Cells are infected with the SARS-CoV-2 virus in 96 well plates and 50% are treated with your test article at various concentrations

– Looking at cytopathic effect (CPE), cell survival endpoints EC50 and TC50

SARS-CoV-2 48hr neutralization assays for antibodies to determine reduction of plaques and viral measurements.

PRNT

– Plaques are visualized and counted using an ELISPOT instrument

– Plaque counts are fitted to a dose-response curve and plaque reduction neutralization test titers (PRNT) expressed in terms of conventional 50% PRNT end-point titers.

ELISA

– For each well, the inhibition of virus by neutralizing antibodies is calculated as the percentage of reduction of the absorbance value in respect of the virus control

– The neutralizing antibody titer is defined as the reciprocal dilution that caused 50% reduction of the absorbance value of the virus control (50% A450 reduction)

– Testing of surface disinfectant sprays and sanitizers against the SARS-CoV-2 strain

– Porous and non-porous material capabilities

– Testing of products against SARS-CoV-2 in suspension

Based on modified/standard industry protocols (see below)

Antimicrobial products-Test for antimicrobial activity and efficacy (JIS Z 280)

Standard Practice to Assess the Activity of Microbicides against Viruses in Suspension (ASTM E1052)

Standard Practice to Assess Virucidal Activity of Chemicals Intended for Disinfection of Inanimate, Nonporous Environmental Surfaces (ASTM E1053)

– Clinical signs such as body weight loss, although no mortality

– Viral load in nasal washes and blood

– Routes of dosage admin include intranasal, inhaled (inhalation), and intraperitoneal

-Virus detection in various tissues

References for this model: iitri.org/covid-19-syrian-hamster-model/

– Favorable model for looking at effects solely in upper respiratory tract

– Infection model only, no clinical signs

– Viral load and shedding in nasal washes

– Routes of dosage admin include intranasal, intraperitoneal, inhaled (inhalation), and intravenous 

References for this model: IITRI ferret studies

– K18-hACE2 transgenic mouse model

Clinical signs such as body weight loss, mortality

– Viral load in nasal washes

Dose range-finding data for the hACE2- transgenic mouse model