ABU DHABI // A combination of common antiviral drugs could provide hope to those infected with the deadly Mers coronavirus after a study of infected monkeys showed positive results.
An experiment treating infected rhesus monkeys with ribavirin and interferon-alpha 2b, which are commonly used to treat chronic hepatitis C and other diseases in humans, showed the medication reduced virus replication and improved the health of the animals.
The finding gives hope in treating the deadly virus, which currently has no cure, said Heinz Feldmann, the study’s co-author.
“As these two drugs are already used in combination in the clinic for other infections, IFN-alpha2b and ribavirin should be considered for the management of Mers-CoV cases,” said Dr Feldmann, who is chief of the laboratory of virology at the US National Institutes of Health’s Rocky Mountain Laboratories in Montana. He is also an expert on emerging viruses and a decade ago investigated the outbreak of Sars, a distant relative of Mers.
Mers has so far led to the deaths of 58 people, including an Emirati in Abu Dhabi.
Dr Asiim Malik, a consultant and head of infectious disease at Mafraq Hospital in Abu Dhabi, described the study as a “very exciting” step because of the lack of existing treatment.
In the study, the cocktail of antiviral drugs was administered to three rhesus monkeys eight hours after they were infected with Mers.
Three infected monkeys did not receive treatment. Those who did had reduced inflammation, fewer injuries to the lungs, fewer copies of the virus, no difficulty breathing and minimal signs of pneumonia in their chest X-rays.
“Taken together, this data suggests that treatment of Mers-CoV-infected rhesus macaques with IFN-alpha2b and ribavirin reduces virus replication, moderates the host response and improves clinical outcome,” the study concluded.
Mers leads to an acute respiratory illness in humans and causes breathing difficulties, diarrhoea and, in about half the cases recorded, death. As with Sars, Mers has flu-like symptoms, but it differs in that it also causes kidney failure. There is no effective therapy or vaccine capable of controlling the infection or limiting its severity.
“The emergence of Middle East respiratory syndrome coronavirus is of global concern,” the study said. “Therapeutic interventions have not been evaluated in vivo; thus, patient management relies exclusively on supportive care, which, given the high case-fatality rate, is not highly effective.
“Given the severity and poor outcome of Mers-CoV infection, combined IFN-alpha2b and ribavirin therapy should be considered as an early intervention therapy for Mers-CoV.”
While experts say it is highly likely that Mers is transferred to humans from animals, it is still unclear exactly which creatures it came from. Differing studies suggest the disease may have spread from bats or camels.
“It seems to be a very promising study since we currently do not have any specific treatment for Mers-CoV infection,” said Dr Malik.
“The only treatment offered at this time is supportive. The fact that the study demonstrated efficacy of agents already used to treat other viral illnesses is also very exciting.
“This finding may set the course for further studies, eventually leading to more information and experience, with specific therapeutic agents for Mers-CoV infection.”
However, despite the study’s promise, more research is needed, he warned.
“The limitation of the study is the fact that the combination antiviral regimen was used to treat disease in animal model that replicated mild to moderate-intensity illness,” the doctor said.
“It remains to be seen if the combination will be as beneficial in severely ill models that would replicate and resemble the most commonly encountered human illness pattern, ie, a severe pneumonia with respiratory failure.
“Despite this, it remains the only antiviral therapy studied in vivo and thus holds a lot of promise.”
So far, the World Health Organisation, which has set up an emergency committee to monitor and control the spread of the virus, has confirmed 136 people have been infected.
Saudi Arabia is the worst hit, with 51 deaths, and the country is being closely monitored this month during the Haj. The Saudi ministry of health said on Saturday there were no recorded cases so far of Mers-CoV among pilgrims.
Cases have also been confirmed in Qatar, Jordan and the UAE and the virus has spread to Britain, France, Germany, Italy and Tunisia.
* Additional reporting from Reuters