Interferon-β and mycophenolic acid are potent inhibitors of Middle East respiratory syndrome coronavirus in cell-based assays

J Gen Virol. 2014 Mar;95(Pt 3):571-577. doi: 10.1099/vir.0.061911-0. Epub 2013 Dec 9.


The Middle East respiratory syndrome coronavirus (MERS-CoV) presents a novel emerging threat to public health worldwide. Several treatments for infected individuals have been suggested including IFN, ribavirin and passive immunotherapy with convalescent plasma. Administration of IFN-α2b and ribavirin has improved outcomes of MERS-CoV infection in rhesus macaques when administered within 8 h post-challenge. However, detailed and systematic evidence on the activity of other clinically available drugs is limited. Here we compared the susceptibility of MERS-CoV with different IFN products (IFN-α2b, IFN-γ, IFN-universal, IFN-α2a and IFN-β), as well as with two antivirals, ribavirin and mycophenolic acid (MPA), against MERS-CoV (Hu/Jordan-N3/2012) in vitro. Of all the IFNs tested, IFN-β showed the strongst inhibition of MERS-CoV in vitro, with an IC₅₀ of 1.37 U ml(-1), 41 times lower than the previously reported IC₅₀ (56.08 U ml(-1)) of IFN-α2b. IFN-β inhibition was confirmed in the virus yield reduction assay, with an IC90 of 38.8 U ml(-1). Ribavirin did not inhibit viral replication in vitro at a dose that would be applicable to current treatment protocols in humans. In contrast, MPA showed strong inhibition, with an IC₅₀ of 2.87 µM. This drug has not been previously tested against MERS-CoV and may provide an alternative to ribavirin for treatment of MERS-CoV. In conclusion, IFN-β, MPA or a combination of the two may be beneficial in the treatment of MERS-CoV or as a post-exposure intervention in high-risk patients with known exposures to MERS-CoV.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Cell Line
  • Chlorocebus aethiops
  • Coronaviridae / drug effects*
  • Coronaviridae / physiology
  • Coronaviridae Infections / drug therapy
  • Coronaviridae Infections / virology*
  • Humans
  • Interferons / pharmacology*
  • Mycophenolic Acid / pharmacology*
  • Vero Cells
  • Virus Replication / drug effects


  • Interferons
  • Mycophenolic Acid