Background and Objective Severe acute respiratory distress syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 , is a member of the coronavirus family. Coronavirus infections in humans are typically associated with respiratory illnesses; however, viral RNA has been isolated in serum from infected patients. Coronaviruses have been identified as a potential low-risk threat to blood safety. The Mirasol Pathogen Reduction Technology (PRT) System utilizes riboflavin and ultraviolet (UV) light to render blood-borne pathogens noninfectious, while maintaining blood product quality. Here, we report on the efficacy of riboflavin and UV light against the pandemic virus SARS-CoV-2 when tested in both plasma and platelets units. Materials and MethodsStock SARS-CoV-2 was grown in Vero cells and inoculated into either plasma or platelet units. Those units were then treated with riboflavin and UV light. The infectious titres of SARS-CoV-2 were determined by plaque assay using Vero cells. A total of five (n = 5) plasma and three (n = 3) platelet products were evaluated in this study. ResultsIn both experiments, the measured titre of SARS-CoV-2 was below the limit of detection following treatment with riboflavin and UV light. The mean log reductions in the viral titres were ≥3Á40 and ≥4Á53 for the plasma units and platelet units, respectively.Conclusion Riboflavin and UV light effectively reduced the titre of SARS-CoV-2 in both plasma and platelet products to below the limit of detection in tissue culture. The data suggest that the process would be effective in reducing the theoretical risk of transfusion transmitted SARS-CoV-2.

BACKGROUND: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has recently been identified as the causative agent for Coronavirus Disease 2019 . The ability of this agent to be transmitted by blood transfusion has not been documented, although viral RNA has been detected in serum. Exposure to treatment with riboflavin and ultraviolet light (R + UV) reduces blood-borne pathogens while maintaining blood product quality. Here, we report on the efficacy of R + UV in reducing SARS-CoV-2 infectivity when tested in human plasma and whole blood products. STUDY DESIGN AND METHODS: SARS-CoV-2 (isolate USA-WA1/2020) was used to inoculate plasma and whole blood units that then underwent treatment with riboflavin and UV light (Mirasol Pathogen Reduction Technology System, Terumo BCT, Lakewood, CO). The infectious titers of SARS-CoV-2 in the samples before and after R + UV treatment were determined by plaque assay on Vero cells. Each plasma pool (n=9) underwent R + UV treatment performed in triplicate using individual units of plasma and then repeated using individual whole blood donations (n=3). RESULTS:Riboflavin and UV light reduced the infectious titer of SARS-CoV-2 below the limit of detection for plasma products at 60-100% of the recommended energy dose. At the UV light dose recommended by the manufacturer, the mean log reductions in the viral titers were ≥ 4.79 ± 0.15 Logs in plasma and 3.30 ± 0.26 in whole blood units. CONCLUSION:Riboflavin and UV light effectively reduced the titer of SARS-CoV-2 to the limit of detection in human plasma and by 3.30 ± 0.26 on average in whole blood. Two clades of SARS-CoV-2 have been described and questions remain about whether exposure to one strain confers strong immunity to the other. Pathogen-reduced blood products may be a safer option for critically ill patients

BackgroundSevere Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has recently been identified as the causative agent for Coronavirus Disease 2019 . The ability of this agent to be transmitted by blood transfusion has not been documented, although viral RNA has been detected in serum. Exposure to treatment with riboflavin and ultraviolet light (R + UV) reduces blood-borne pathogens while maintaining blood product quality. Here, we report on the efficacy of R + UV in reducing SARS-CoV-2 infectivity when tested in human plasma and whole blood products. Study design and methodsSARS-CoV-2 (isolate USA-WA1/2020) was used to inoculate plasma and whole blood units that then underwent treatment with riboflavin and UV light (Mirasol Pathogen Reduction Technology System, Terumo BCT, Lakewood, CO). The infectious titers of SARS-CoV-2 in the samples before and after R + UV treatment were determined by plaque assay on Vero E6 cells. Each plasma pool (n = 9) underwent R + UV treatment performed in triplicate using individual units of plasma and then repeated using individual whole blood donations (n = 3). ResultsRiboflavin and UV light reduced the infectious titer of SARS-CoV-2 below the limit of detection for plasma products at 60-100% of the recommended energy dose. At the UV light dose recommended by the manufacturer, the mean log reductions in the viral titers were � 4.79 ± 0.15 Logs in plasma and 3.30 ± 0.26 in whole blood units. ConclusionRiboflavin and UV light effectively reduced the titer of SARS-CoV-2 to the limit of detection in human plasma and by 3.30 ± 0.26 on average in whole blood. Two clades of SARS-CoV- PLOS ONE

The COVID-19 pandemic has generated intense interest in the rapid development and evaluation of vaccine candidates for this disease and other emerging diseases. Several novel methods for preparing vaccine candidates are currently undergoing clinical evaluation in response to the urgent need to prevent the spread of COVID-19. In many cases, these methods rely on new approaches for vaccine production and immune stimulation. We report on the use of a novel method (SolaVAX) for production of an inactivated vaccine candidate and the testing of that candidate in a hamster animal model for its ability to prevent infection upon challenge with SARS-CoV-2 virus. The studies employed in this work included an evaluation of the levels of neutralizing antibody produced post-vaccination, levels of specific antibody sub-types to RBD and spike protein that were generated, evaluation of viral shedding post-challenge, flow cytometric and single cell sequencing data on cellular fractions and histopathological evaluation of tissues post-challenge. The results from this preliminary evaluation provide insight into the immunological responses occurring as a result of vaccination with the proposed vaccine candidate and the impact that adjuvant formulations, specifically developed to promote Th1 type immune responses, have on vaccine efficacy and protection against infection following challenge with live SARS-CoV-2. This data may have utility in the development of effective vaccine candidates broadly. Furthermore, the results of this preliminary evaluation suggest that preparation of a whole virion vaccine for COVID-19 using this specific photochemical method may have potential utility in the preparation of one such vaccine candidate.

Background and objectives Convalescent plasma (CP) has been embraced as a safe therapeutic option for coronavirus disease 2019 (COVID-19), while other treatments are developed. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is not transmissible by transfusion, but bloodborne pathogens remain a risk in regions with high endemic prevalence of disease. Pathogen reduction can mitigate this risk; thus, the objective of this study was to evaluate the effect of riboflavin and ultraviolet light (R + UV) pathogen reduction technology on the functional properties of COVID-19 CP (CCP). Materials and methods COVID-19 convalescent plasma units (n = 6) from recovered COVID-19 research donors were treated with R + UV. Pre-and post-treatment samples were tested for coagulation factor and immunoglobulin retention. Antibody binding to spike protein receptor-binding domain (RBD), S1 and S2 epitopes of SARS-CoV-2 was assessed by ELISA. Neutralizing antibody (nAb) function was assessed by pseudovirus reporter viral particle neutralization (RVPN) assay and plaque reduction neutralization test (PRNT).Results Mean retention of coagulation factors was ≥70%, while retention of immunoglobulins was 100%. Starting nAb titres were low, but PRNT 50 titres did not differ between pre-and post-treatment samples. No statistically significant differences were detected in levels of IgG (P ≥ 0Á3665) and IgM (P ≥ 0Á1208) antibodies to RBD, S1 and S2 proteins before and after treatment.Conclusion R + UV PRT effects on coagulation factors were similar to previous reports, but no significant effects were observed on immunoglobulin concentration and antibody function. SARS-CoV-2 nAb function in CCP is conserved following R + UV PRT treatment.