Treating Middle East respiratory syndrome coronavirus (MERS-CoV) infected rhesus macaques with a common antiviral drug combination reduces viral replication, reports a study published this week in Nature Medicine. The findings offer hope that the combination therapy could also be effective in humans.
MERS-CoV causes an acute respiratory illness in humans and has killed about half of the individuals known to be infected. Presently there is no effective therapy or vaccine capable of controlling the infection or limiting its severity. Interferon signaling is an important antiviral defense mechanism and interferon alpha-2b and ribavirin are used in the management of other diseases, such as hepatitis C infection. Its combination use has been reported to inhibit replication of MERS-CoV in cells in culture, as well.
Heinz Feldmann and colleagues infected rhesus macaques with MERS-CoV and then eight hours later treated with interferon alpha-2b and ribavirin. The monkeys receiving the combination therapy showed substantially less lung injury compared with untreated infected monkeys, as well as lower levels of inflammatory immune responses and lower viral load in lungs. The authors also found differences in gene expression in the lungs of treated monkeys compared with untreated ones that may account for some of the differences in pathophysiological response. These findings, in the only known animal model of MERS-CoV infection, lend support to the potential clinical application of interferon alpha-2b and ribavirin therapy for treatment of this infection in humans.