Inactivation of Middle East respiratory syndrome coronavirus (MERS-CoV) in plasma products using a riboflavin-based and ultraviolet light-based photochemical treatment

Transfusion. 2016 Dec;56(12):2948-2952. doi: 10.1111/trf.13860. Epub 2016 Nov 2.


Background: Middle East respiratory syndrome coronavirus (MERS-CoV) has been identified as a potential threat to the safety of blood products. The Mirasol Pathogen Reduction Technology System uses 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 MERS-CoV when tested in human plasma.

Study design and methods: MERS-CoV (EMC strain) was used to inoculate plasma units that then underwent treatment with riboflavin and UV light. The infectious titers of MERS-CoV in the samples before and after treatment were determined by plaque assay on Vero cells. The treatments were initially performed in triplicate using pooled plasma (n = 3) and then repeated using individual plasma units (n = 6).

Results: In both studies, riboflavin and UV light reduced the infectious titer of MERS-CoV below the limit of detection. The mean log reductions in the viral titers were ≥4.07 and ≥4.42 for the pooled and individual donor plasma, respectively.

Conclusion: Riboflavin and UV light effectively reduced the titer of MERS-CoV in human plasma products to below the limit of detection, suggesting that the treatment process may reduce the risk of transfusion transmission of MERS-CoV.

MeSH terms

  • Animals
  • Blood Safety*
  • Blood-Borne Pathogens / drug effects
  • Blood-Borne Pathogens / radiation effects
  • Chlorocebus aethiops
  • Coronavirus Infections / prevention & control
  • Coronavirus Infections / transmission
  • Humans
  • Middle East Respiratory Syndrome Coronavirus / drug effects*
  • Middle East Respiratory Syndrome Coronavirus / pathogenicity
  • Middle East Respiratory Syndrome Coronavirus / radiation effects*
  • Plasma / virology
  • Riboflavin / pharmacology
  • Ultraviolet Rays / adverse effects
  • Vero Cells
  • Viral Load / drug effects
  • Viral Load / radiation effects
  • Virus Inactivation* / drug effects
  • Virus Inactivation* / radiation effects


  • Riboflavin