Efficient Inactivation of SARS-CoV-2 in Human Plasma with Amotosalen and Ultraviolet a Light Treatment

Background/Case Studies: Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) was identified in January 2020 as the responsible agent for COVID-19 First recognized in late 2019, the COVID-19 epidemic developed into a pandemic with, as of July 23, 2020, more than 15 million cases and 600,000 deaths reported globally SARS-CoV-2 RNA was detected in blood samples and blood components from asymptomatic blood donors including frozen plasma units and platelet concentrates This suggests that SARS-CoV-2 may be a potential bloodborne pathogen and pathogen reduction offers potential to reduce the risk of transfusion transmission We investigated the efficacy of amotosalen/UVA light to inactivate SARS-CoV-2 in human plasma Study Design/Methods: Five pools of whole-blood derived human plasma units (630-650 mL each) were inoculated with a local clinical isolate (SARS-CoV-2/ human/SAU/85791C/2020) with a 1:100 dilution Spiked pools were used to evaluate the efficacy of amotosalen/ UVA treatment (INTERCEPT® Blood System, Cerus Corporation, Concord, U S A ) to inactivate SARS-CoV-2 in plasma Infectious and genomic viral titers were assessed by plaque assay and quantitative PCR (Altona Diagnostics, Hamburg, Germany), respectively, in spiked and treated samples in parallel with positive and negative controls Results/Findings: Treatment of spiked plasma (titer of the viral stock: 5 6±0 2 log10 pfu/mL) with amotosalen/ UVA light resulted in complete inactivation of infectious viral titer with mean log reduction of >3 3±0 2 log10 pfu/mL No viral replication or cytopathic effect (CPE) was observed in cells inoculated with inactivated samples even after 9 days of incubation and three successive passages Evaluation of genomic titer expressed in genome equivalent (GEq/mL) in inactivated samples showed equivalent reduction to the limit of detection of 7 10±0 2 log10 GEq/mL Conclusions: Complete and efficient inactivation of SARS-CoV-2 was observed with amotosalen/UVA light treatment of spiked human plasma units suggesting that treatment of plasma with this pathogen reduction technology could reduce the risk of transfusion-transmitted SARS-CoV-2 infection These findings are consistent with prior inactivation data with amotosalen/UVA for other human-pathogenic coronaviruses (SARS-CoV-1 and MERS-CoV) in platelets and plasma